Lesson 1 HEAT I. - St. Claret School - Physics... · · 2014-11-18Lesson – 1 HEAT I. Fill in the blanks:- ... Metals with different linear expansion coefficient. (b) ... Write

Question Bank

Physics

Lesson – 1

HEAT

I. Fill in the blanks:-

1. Heat is a form of _________________.

2. Unit of heat capacity is ____________.

3. Unit of specific heat is ____________.

4. On heating a rod, its length ___________.

5. Unit of latent heat is ____________.

6. Expression for latent heat of fusion is ______________.

7. Formula for specific heat is ___________.

8. Formula for thermal capacity is _____________.

9. Relation between thermal capacity and specific heat is __________.

10. When we rub our palms, _______ energy is converted to heat.

11. When electric current is passed through a coil heat is obtained from _______ energy.

12. The type of glass used to make cooking vessels which has low expansion is __________.

II. Choose the correct answer

1. Bimetallic strip is made up of

(a) Metals with different linear expansion coefficient.

(b) Metals with same linear expansion coefficient.

(c) Metals with same superficial expansion coefficient.

(d) Metals with different length.

2. Specific heat depends on

(a) Nature of the material (b) Mass of material (c) Shape of material (d) Colour of the material

3. Unit of coefficient of linear expansion.

(a) K-1

(b) N-1

(c) J-1

(d) K

4. In a thermostat device which parameter remains approximately constant?

(a) Volume (b) Pressure (c) Temperature (d) Mass

5. Density of water is maximum at

(a) 0oC (b) 4

oC (c) 4K (d) 100

oC

6. The ratio between α, β and γ is

(a) 3:2:1 (b) 2:1:3 (c) 1:2:3 (d) 2:3:1

7. Type of expansion found in gases is

(a) Linear Expansion (b) Superficial Expansion (c) Cubical (d) All the above

III. Answer the following in one sentence:-

1. Give an example to show that physical state of the substance changes on heating.

2. Give an example for the chemical change of the substance on heating.

3. What is thermal expansion?

4. When railway lines are laid, space is left between successive rails. why?

5. Crack is developed in glass when hot water is poured in it. Give reason.

6. What is thermostat?

7. Name two devices which uses thermostat.

8. Write an adverse effect of anomalous expansion of water.

9. Define thermal capacity of the substance.

10. Define specific heat of the substance.

11. Define latent heat of fusion.

12. Define latent heat of vapourisation.

13. Define latent heat.

IV. Answer the following in two sentence:-

1. Mention the four effects of heat.

2. What is linear expansion? Write the formula for coefficient of linear expansion.

3. What is superficial expansion? Write the formula for coefficient of superficial expansion.

4. What is cubical expansion? Write the formula for coefficient of cubical expansion.

5. Mention the types of thermal expansion found in solids.

6. Give two illustrations of thermal expansion in day to day life.

7. What is bimetallic strip? Mention its principle of working.

8. What is global warming?

9. What are the effects of global warming?

10. Steam at 100˚ C causes severe burns than water at 100˚ C. Give reason.

11. When a piece of ice is added to juice, the juice cools. Why?

12. Ice at 0˚ C is a better coolant than water at 0˚ C. Justify.

13. How much heat energy is required to raise 2 kg of water from 20˚ C to its boiling point at 100˚c.

Specific heat of water is 4200 JKg-1

K-1

.

V. Answer the in brief :-

1. Describe an experiment to demonstrate the linear expansion in solids.

2. Describe an experiment to demonstrate the cubical expansion in solids.

3. List three consequences of high specific heat capacity of water.

4. The bridge is constructed of steel and is 2.5 km long. The linear expansively of steel is 11×10-6

K-1

. The

minimum winter temperature may be as low as 0˚ C and the maximum temperature as high as 40˚ C. What

distance must be allowed for the change in length of the

bridge?

5. How much heat energy is liberated when 20 kg of water freezes to form ice at 0˚ C. Latent heat of ice

= 336000 JKg-1

.

6. The length of a brass scale is 1m at 28˚ C. If the coefficient of linear expansion is 18×10-6

C-1

. What is its

new length at 68˚ C.

7. A body of mass 0.5 Kg requires 3000 J of heat in order to raise its temperature from 35˚ C to 45˚ C.

Calculate its specific heat.

8. A metal rod of length 0.5 m at 20˚ C becomes 0.5006 m at 95˚ C. Find the coefficient of linear expansion.

VI. Answer elaborately:-

1. Derive the formula for the coefficient of linear expansion.

2. What is anomalous expansion of water? How it is useful for aquatic lives in polar region.

Lesson -2

Nature of Light


1. Light has _______ and _________ nature.

2. Light waves travel in the form of _________ wave.

3. Electromagnetic waves are ___________ waves.

4. Energy is transported from the source to its surroundings either by ________ motion or by ________

motion.

5. Mechanical wave requires a ________ to travel.

6. According to Huygens light travels in the form of __________ wave.

7. Huygens considered __________ as the imaginary medium.

8. According to Max Plank in light, emission or absorption of energy takes place in __________ units.

9. A photon is characterized by either a ________ or ________.

10. The speed of light is ___________.

11. The unit of frequency is __________.

12. Unit of wavelength is ____________.

13. _________ experiment showed that vacuum does not contain ether medium.

II. Choose the correct answer

1. The packets of energy are called __________

a) Electrons b) Neutrons c) photons d) positrons

2. Corpuscles are the tiny particles of __________

a) light b) sound c) waves d) radiation

3. Which of the following formula represent the energy of photon?

a)

hcE b)

hcE

c)

c

hE

d)

hE

4. Which among the following characteristics of light could not be explained by corpuscular

theory?

a) reflection b) refraction c)diffraction d) dispersion

5. The value of Plank’s quantum constant is ____________.

a) 6.626 x 1034

JS b) 6.626 X 10-34

JS c) 6.266 X 1034

JS d) 6.266 X 10-34

JS

6. The relation between wavelength, frequency and wave velocity is _____________

a) c b) c c) c d) c

7. Newton called tiny light particles as ______________

a) Photon b) Quantum c) Corpuscles d) Ether

8. Corpuscular theory was proposed by ________________.

a) Huygen b) Maxwell c) Planck d) Newton

9. Which among the following can be explained by corpuscular theory?

a) Diffraction b) Dispersion c) Interference d) Polarization

III. Answer the following: (1m)

1. What is light?

2. Who proposed wave theory?

3. What is mechanical wave?

4. Who proposed corpuscular theory?

5. Which theory of light proposed the presence of ether medium for propagation of light?

6. Which theory explains all the characteristics of light?

7. What is meant by electromagnetic radiation?

8. What is electromagnetic wave?

9. Name any two characteristics of light explained by Huygen’s wave theory.

10. What is dual nature of light?

11. Who proposed electromagnetic theory?

12. Who proposed quantum theory?

IV Answer the following in two sentence:-

1. Can the wave theory of light explain the phenomenon of photoelectric effect. Justify.

2. Light energy is propagated in the form of particles having wave nature. Justify the statement

using quantum theory of light.

3. State Maxwell’s Electromagnetic theory.

4. Why was electromagnetic theory discarded?

5. Compare Newton’s corpuscular theory with plank’s quantum hypothesis.

V Answer the in brief :-

1. What is a wave? Mercury street lamp gives blue light of wavelength 436nm. What is its

frequency?

2. When sodium salts are burned it emits yellow light of wavelength around 588nm. Calculate

thefrequency of yellow light of wavelength 588nm.

3. Sodium vapour lamp gives yellow light of wavelength 589.3nm. What is the energy of one

photon of light?

VI Answer elaborately:-

1. State Huygens wave theory. Why was Huygens theory discarded?

2. State corpuscular theory of light. Why was it discarded?

Lesson -3

Lens

I Fill in the blanks:-

1. A ray of light passes undeviated after refraction from a thin lens when it is incident at

________.

2. Virtual enlarged and erect image is formed on the same side of an object in the convex lens.

Then the position of the object is _________.

3. The distance between principal focus and the optic centre of a lens is called its __________.

4. Lens is also called ___________.

5. Focal length is represented by the letter ___________.

6. The ___________ lens is used as a magnifying lens.

7. _______________ lens always forms virtual image.

II Choose the correct answer

1. A transparent material which is thicker in the middle and thinner at the edges is called ________.

a) Concave lens b) Plano concave lens c) Convex lens d) Convexoconcave lens

2. Where should an object be placed in front of a convex lens to get real image of the size of the

object?

a) At infinity b) At principal focus c) At twice the focal length d) Between optic centre and

principal focus.

3. The image of an object formed by concave lens is ______________.

a) Virtual, inverted and diminished

b) Virtual, upright and diminished

c) Virtual, inverted and enlarged

d) Virtual, upright and enlarged

4. An object is placed at the distance of 5cm from a convex lens of focal length 10cm. The image

formed is

a) real and inverted b) real and enlarged c) virtual and diminished d) virtual and enlarged

5. In a spotlight object is placed ______________ of the lens.

a) At F b) At 2F c) Between F & 2F Beyond 2F.

III. Answer the following: (1m)

1. What is a lens?

2. What is a ray of light?

3. What is a beam of light?

4. What is a parallel beam of light?

5. What is a focal length?

6. At what position the object should be placed with respect to the lens in a microscope.

IV Answer the following in two sentences:-

1. Define principal focus of a convex lens.

2. Define principal focus of a concave lens.

3. Write the difference between real and virtual images.

4. Write the nature and position of the image formed by a convex lens when the object is at F?

a. Mention its practical application.

5. How should two converging lenses be placed so that a parallel beam becomes parallel after passing

through two lenses?

6. Draw a ray diagram to show how a converging lens is able to form the image of the sun.

V Answer the in brief :-

1. Define the following:-Aperture b) Optic centre c) principal axis

2. List the different types of convex and concave lenses.

3. Draw a ray diagram and represent the characteristics of the image formed by a convex lens when

the object is beyond 2F of the lens?


the object is at 2F of the lens?


the object is between F and 2F of the lens?

6. Draw a ray diagram and represent the characteristics of the image formed by a concave lens

when the object is placed at F?

7. Explain with the help of ray diagram, why the convex lens is also called a converging lens.

VI Answer elaborately:-

1. List any four new Cartesian sign conventions for lenses?

2. a) What is the speed of light in vacuum?

a) Calculate the focal length of the convex lens which produces a real image at a distance of

30cm of an object placed 20cm from the lens?

3. An object is placed at a distance 10cm from a convex lens of focal length 20cm. Find the nature

of the image.

4. Calculate the focal length of a convex lens which produces a real image at a distance of 30cm of

an object placed 20cm from the lens.

5. Concave lens has focal of 15cm. At what distance should an object from the lens be placed so

that the image is at 10cm from the lens.

6. An object is placed at a distance of 64cm from a white screen. By placing a convex lens at a

distance of 32cm from the object, it is found that a distant image of the object is formed on the

screen. Calculate the focal length of the lens.

7. A concave lens of 20cm focal length forms an image 15cm from the lens. Calculate the distance

of the object from the lens.

Lesson – 4

Optical instruments

I. Choose the correct answer:-

1. Compound microscope is used to see

a. Germs

b. Plants

c. Stars

d. Craters.

2. The optical instrument which is used to view cricket match is

a. Simple microscope

b. Compound microscope

c. Astronomical telescope

d. Binocular

3. Telescopes make the far objects appear

a. Farther

b. Nearer

c. Highly magnified

d. Erect

4. The type of lens used as a simple microscope.

a. Binocular lens

b. Plano concave lens.

c. Concave convex lens.

d. Convex lens.

5. The final image in a compound microscope is

a. Real of inverted

b. Virtual and inverted

c. Real and erect

d. Virtual and erect

II. Fill in the blanks.

1. A horologist uses ____________to observe the small parts of a watch.

2. A palmist uses ___________ to observe the pattern of lines on the palm.

3. The first telescope was designed by________.

4. Name of an optical instrument which is used to see erect image of a distant object is ________.

5. The type of lens used to make objective of an astronomical telescope is___________.

6. The lens placed towards the object in an optical instrument is called_________.

III. Answer the following: (1mark)

1. What is a simple microscope?

2. Write the uses of microscopes?

3. What is a photographic camera?

4. Write the type of image formed in simple microscope?

5. Write the type of image formed in compound microscope?

6. Write the type of image formed in astronomical microscope?

7. Write the type of image formed in a binocular?

IV. Answer the following: (2 marks)

1. Define magnification. Write its formula?

2. Name the two types of telescopes and microscopes?

3. How is the image stored in a digital camera?

4. Write two differences between a binocular and terrestrial telescope.

5. A telescope of a binocular has two total internal reflecting prisms. Give reasons.

6. Write any two differences between a simple microscope and a compound microscope?

V. Answer the following: (3 marks)

1. Explain the formation of images in simple microscope with neat diagram.

2. What are terrestrial telescopes? Explain its working.

3. Draw neat ray diagram of terrestrial telescope.

4. Explain the construction of binocular with neat diagram.

VI. Answer the following: (4marks)

6. List 4 uses of simple microscope.

7. What is a compound microscope? Draw a ray diagram of compound microscope.

8. Explain the construction and working of the compound microscope.

9. What is an Astronomical telescope? Draw a neat ray diagram of astronomical telescope.

10. Explain the working of camera with neat diagram.

Lesson – 5

Circular motion

I . Choose the correct answer.

1. The force responsible for drying of clothes in a washing machine is

a. Gravitational force.

b. Centripetal force.

c. Centrifugal force.

d. Electrostatic force.

2. Force involved in uniform circular motion is given by

a. mv2/r

b. mvr

c. mr2/v

d. mrv2

3. A cyclist moving circular track leans towards the centre.

a. To gain in momentum.

b. To gain necessary centripetal force.

c. To gain necessary centrifugal force.

d. To gain speed.

II. Fill in the blanks

1. At any point in a circular motion the direction of linear velocity of the particle is _________.

2. The direction of centripetal force is _____________.

3. Linear speed of a particle is in a uniform circular motion is ____________.

4. The direction of centrifugal force is __________.

5. Centrifugal force is ___________in magnitude to the centripetal force.

6. Centrifugal force is ____________ in direction to the centripetal force.

III. Answer the following: (1 mark)

1. Identify the type of circular motion in the following

a. Spinning top.

b. Electrons revolving around a nucleus.

2. What is a circular motion?

3. Identify the types of circular motion in the following.

a. Compact disc in a player.

b. Pulley used to draw water in a well.

4. What is axis of rotation?

5. What is centripetal acceleration?

IV. Answer the following (2 marks)

1. A body moving in a circular path with constant speed is an accelerated motion. Why?

2. Define centripetal force. Write the expression for it.

3. Cyclist in a circular path leans towards the centre. Give reason.

4. Name two types of circular motion.

5. List the types of forces responsible for centripetal force.

6. How does centrifugal force helps in drying clothes in a washing machine.

V. Answer the following (3marks)

1. Write the difference between revolutionary motion and rotatory motion. Give one example for each.

2. Give two applications of centrifugal force.

3. Name the types of force responsible for the centripetal force in the following.

a. A bucket of water is tied to a string and spun in a circle.

b. Moon orbits the earth.

c. Electrons revolving around the nucleus.

VI. Answer the following -4 marks

1. What are the factors on which centrifugal force depends on? How do they influence centrifugal

force? Give on example illustration of a centripetal force.

Lesson – 6

Electro Magnetic Radiation

I Fill in the blanks:-

1. The disturbance created in a medium travel in the form of a _______________.

2. The frequency of the Radio waves transmitted from AIR, Bangalore is _________.

3. Microwaves are produced by special vacuum tubes called ___________.

4. ______________ Radiation is used in Remote control of television.

5. Ultraviolet rays were discovered by ______________.

6. Radioactive elements emit _____________ rays.

7. Electric and magnetic field in Electromagnetic wave are mutually ____________ to each other.

8. The range of wavelength of visible light is ___________.

II. Choose the correct answer:-

1. The region of the Electromagnetic spectrum with longer wavelength

a) Radio waves

b) UV rays

c) Gamma rays

d) IR rays

2. IR radiation was detected by

a) William Herschel

b) Hertz

c) Wilhelm Roentgen

d) Ritter J. C.

3. Long exposure to UV rays causes

a) Fracture

b) Skin cancer

c) Mutation in cells

d) Paralysis

4. Surgical instruments are sterilized by exposing them to

a) IR radiations

b) X rays

c) Gamma rays

d) UV rays

5. In vacuum Electromagnetic waves travel at the speed of

a) 3 x 108 m/sec

b) 3 x 106 m/sec

c) 3 x 10-8

m/sec

d) 3 x 1018

m/sec

III. Answer the following:- (1m)

What are mechanical waves?

What is an Electromagnetic wave?

List the types of Electromagnetic waves.

How is radio waves produced?

Give two sources of visible spectrum.

Who discovered X-Rays?

Name the electromagnetic radiation use to show the bone structure.

IV. Answer in 2 or 3 sentences (2m)

1. Draw a neat diagram of an electromagnetic wave?

2. What is an Electromagnetic spectrum? Give the range of the Electromagnetic rays in terms of

wavelength.

3. IR radiation photography is suitable during night and in mist and fog. Give reason.

4. Write the natural and artificial sources of IR radiations?

5. What is a visible spectrum? Who discovered it?

V. Answer briefly: (3m)

1. In ovens, only the food gets heated up but not the vessel. Give reason.

2. List 3 uses of microwaves.

3. How is the visible light produced in a fluorescent lamp?

4. List 3 uses of UV rays.

5. How are X rays produced. Draw a neat diagram of a X ray tube.

6. Who discovered Gamma rays? Write its properties?

VI. Answer elaborately: (4m)

1. List 4 properties of electromagnetic waves.

2. List 4 uses of radio waves.

3. Write the hazards caused by the following: a) microwaves b) X rays c) Gamma rays d) UV rays.

Lesson – 7

Basics of computers


1. _________________ is considered as India’s first Supercomputers.

2. ___________________ is a supercomputer built by the Indian Space Research Organisation.

3. __________________ allows to make selections by simply touching the display screen.

4. ________________ is the video camera which records motion picture and directly send to the

computer.

5. ________________ is needed to convert assembly language into machine language.

6. _______________ is an audio input device which sends audio signals to a computer.

7. ________________ is needed to convert High Level Language to machine language.


1. Which operation is not performed by computer?

a) Inputting

b) Processing

c) Controlling

d) Understanding

2. Central Processing unit is the combination of

a) Control and storage

b) Control and output unit

c) Arithmetic logic and input unit

d) Arithmetic logic, storage and control unit

3. The language that is directly understood by the computer without translation program is

a) Machine language

b) Assembly language

c) High level language

d) Medium level language


1. What is a keyboard?

2. What is a function of a scanner?

3. Write the function of Bluetooth?

4. List 4 output devices.

5. What is a program?


1. What is a computer?

2. Differentiate between optical mark reader and magnetic card reader.

3. How are computers useful in the field of medicine?

4. What is a Laptop?

5. Differentiate between system software and application software.

6. Give 2 examples of Operating system software.

7. Give 2 examples of Utility software.

8. Give 2 examples of Package software.

9. What is a High Level Language? Give one example.

10. What is the difference between Hardware and Software of a computer?


1. Draw a block diagram of a computer.

2. List the primary and secondary storage devices.

3. Why is software essential to run the computer? Discuss.

4. Explain the function of Input, Output and storage of a computer.

5. How are computers classified based on the size and power.

6. What is a Biometer?


1. Differentiate between RAM and ROM.

2. Classify the following into Input and Output devices and explain how they are used to perform input

and output functions. a) mouse b) printer c) speaker.


and output functions. a) projector b) trackball c) optical mouse reader.


and output functions. a) plotters b) light pen c) Joystick.

5. Explain the function of CPU?

6. Write 4 applications of computer?

7. Write short notes on tablet?

Lesson – 8

Properties of matter


1. Anything that has mass and occupies __________________ is called matter.

2. The most ductile metal is ______________.

3. Modulus of elasticity is also called as _________________.


1. Most malleability metal

a) Silver b) gold c) Aluminium d) Magnesium

2. The SI unit of stress is ______________.

a) Kgm-2

b) Nkg-1

c)Nm-2

d) Nm-1

3. Asha saw a pearl mala which was made of gold. She was wondering how the gold can be made to go

through the pearls. Which property of gold is related to?

a) Malleability b) ductility c) Rigidity d) elasticity


1. What is deformation?

2. State Hooke’s law.

3. Define co-efficient of elasticity.

4. Write the formula for modulus of elasticity?

5. When is a body said to be perfectly elastic?


1. What are stress and strain?

2. Differentiate between malleability and ductility.

3. The elastic properties of steel are essential while designing a building. Give reason.

4. A rubber tube is longer when suspended vertically than when placed horizontally on a table. Give

reason.


1. What is elasticity?

2. Distinguish between Rigid, Elastic and plastic materials with one example.

3. Explain tensile stress and longitudinal strain with neat diagram.

4. Explain shear stress and shearing strain with neat diagram.

5. Explain compressive stress and compressive strain with neat diagram.

6. State the different moduli of elasticity.


1. Explain the behaviour of solids.

2. List four applications of elastic behaviour of materials.

Lesson – 9

Gravitation


1. Value of Gravitational constant is G= ________________.

2. Acceleration due to gravity is independent of _______________.

3. According to Newton’s law of gravitation F= ________________.

4. In vacuum if a coin and feather is released from the same height, then they will reach the ground

_______________.

5. The value of acceleration due to gravity at poles is approximately equal to _________________.

6. The value of acceleration due to gravity at equator is approximately equal to _________________.

7. On the surface of the earth the value of g at equator is _________ than at poles.


1. Gravitational force is always ________________.

a) Attractive b) repulsive c) neither attractive nor repulsive d) Zero

2. Unit of acceleration due to gravity is

a) ms-1

b) ms-2

c) ms-3

d) ms-4

3. As the altitude increases, the acceleration due to gravity

a) remains constant b) becomes zero c) decreases d) increases

4. The relation connecting acceleration due to gravity and gravitational constant is _____________.

a)

b)

c) d)

5. SI unit of gravitational constant is

a) N2m

2kg

2 b) Nmkg

2 c) N

2mkg

-2 d) Nm

2kg

-2

6. At the centre of the earth acceleration due to gravity is

a) Zero b) infinity c) 9.8 d) 98


1. Define force.

2. What is gravitational force?

3. Define Gravitational constant G.

4. Newton’s law is also called Universal law. Why?

5. What is gravity?

6. The value of g varies from place to place on the earth’s surface. Why?


1. Differentiate between contact and action-at-a-distance forces.

2. State Newton’s law of Gravitation.

3. What is acceleration due to gravity? Write its symbol and average value?


1. List three contact and action-at-a distance forces.

2. Group the following forces in to contact and action-at-a distance forces.

a) Force of attraction between +ve and –ve charges.

b) The tension force in the rope of crane.

c) Force between the Earth and moon.

3. Group the following forces in to contact and action-at-a distance forces.

a) Magnetic force between two magnets.

b) Electric force between nucleus and electron.

c) The force acting on a object sliding along the inclined plane.

4. Derive Newton’s law of Gravitation.

5. Mention the effect of altitude and depth on the value of acceleration due to gravity. Give the

corresponding mathematical relation.


1. Explain with an experiment to show that all objects starting from rest fall in vacuum with equal

rapidity.

2. Describe the experiment with simple pendulum to determine the value of acceleration due to gravity

with neat diagram.

3. Derive an expression to find the value of g on the surface of the earth.

4. A sphere of mass 10kg is attracted by another sphere of mass 150kg, with a force equal to 1.28 x 10-

6 N, when their centres are separated by a distance of 0.28m. Calculate the gravitation constant G.

5. Estimate the mass of the earth, given the radius of the earth is 6.4 x 106m, acceleration due to

gravity is 9.8 m/s2 and the gravitational constant is 6.67 x 10

-11 SI units.

Lesson – 10

Photoelectric Effect and Laser


1. The energy of a photon is given by the formula _______________.

2. Light energy can be converted into electricity by ________________.

3. The minimum frequency of incident radiation to produce photo electric effect is called

______________________.

4. The KE of photo electrons is directly proportional to ________________.

5. Laser light when passed through a glass prism cannot produce band of colours because it

is_______________.

6. Laser is an acronym which stands for ________________.

7. MASER is an acronym which stands for ________________.

8. _____________ produced the first working laser using ruby crystal in 1960.

9. _______________ laser is used to drill holes through diamond.

10. ______________ is the key element that has made laser eye surgery possible.

11. ______________ laser is used in CD players.


1. The electromagnetic radiation that can produce photoelectric effect in almost all metals is.

a) Radio wave b)visible light c)Infrared rays d)Gamma rays

2. A person wearing a black shirt and a white cap is standing in front of a T.V. camera. The part of the

photocell which captures the image of his cap emits more no of photoelectrons. This is related to.

a) Frequency b) Intensity c) Velocity d) Wavelength.

3. Laser is used in finding the distance between the moon and the earth. The property of laser used in

this process is.

a) Monochromaticity b)Non diverging nature c) High energy density d) Higher velocity

4. The following cannot be explained by wave nature of light.

a) Interference b) Photo electric effect c)Diffraction d) Refraction


1. What are free electrons?

2. What are photo electrons?

3. What is a photocell?

4. What are solar energy devices?

5. What is a laser?

6. Can you call all single coloured light as laser?

7. What is Tyndall effect?

8. What do you mean by energy density?

9. What is a laser beam Holograph?


1. Differentiate between thermionic emission and photo electric effect.

2. Radio waves are found in the surroundings. But they do not produce photoelectric effect on metals.

Why?

3. Iron sheets when exposed to sunlight cannot produce photo electric effect. Why?

4. Zinc plate when exposed to UV rays can produce photoelectrons. When zinc plate is exposed to X-

rays also produce photoelectrons. What is the difference between the photo electrons produced in

both cases?

5. Photocells which are used in solar electric energy panels produce less no of electrons during cloudy

weather why?

6. A zinc plate of 4sq cm area is exposed to 1)40 watt UV lamp 2)60 watt UV lamp.Both are at same

distance from the zinc plate. What is the difference in KE of photo electrons in both cases?

7. Sodium metal can produce photo electric effect for ordinary visible light. Why?

8. Why laser light is called monochromatic?

9. Write 4 properties of laser?

10. Ordinary keychain laser light should not be viewed directly. Why?

11. Laser is used in cutting metals. Why?

12. Silicon voltaic cells are used in solar electrical energy devices. Why?

13. Suggest any 2 situations in which photocells can be used as automatic switches.

14. State the factors on which the following depend

i) KE of photoelectrons

ii) No. of photoelectrons


1. Give Einstein’s explanation on photoelectric effect.

2. Why wave theory cannot explain photoelectric effect?

3. What is dual nature of light?

4. List 3 applications of photoelectric effect.

5. Distinguish between ordinary light and laser light.

6. Explain the following. i) spontaneous emission ii) excitation

7. Explain the following. i) population inversion ii) pumping iii) active systems

8. Write the 3 types of lasers with an example each.

9. The time taken by laser to travel from tower A to tower B and then reflect back to tower A from a

mirror on tower B is 0.0001 sec. Calculate the distance between 2 towers.


1. Write 4 properties of photoelectric effect.

2. List few applications of photocells.

3. Write 4 applications of laser?

4. Explain the principle of production of laser with neat diagram.

5. Explain helium-neon gas laser tube with neat diagram.

6. Explain the experiment to demonstrate photoelectric effect.

Lesson – 11

Electricity


1. Electrica is a Latin word which means ___________.

2. The smallest and lightest particle of an atom is the _________.

3. The SI unit of electromotive force is __________.

4. Lightning can travel at the speed of ___________.

5. Neutrons are electrically _______________.

6. One coulomb per second is called _____________.

7. Potential difference is also called _________.

8. The practical unit of electricity is ___________.


1. Electricity is a form of _______________.

a)Force b) Energy c) Tension d) Shock

2. Potential difference is also called _______________.

a) Volts b) Voltage c) Coulomb d) Ampere

3. Resistance of a wire is r ohms. The wire taken is double its length, then its initial resistance in ohms

will be

a)

b) 4r c) 2r d)

4. Conversion of sound into electrical impulses.

a) Microphone b)speaker c) fan d) Dry cell

5. Conversion of electricity into mechanical energy.

b) Microphone b)speaker c) fan d) Dry cell


1. Name the two types of charges in nature.

2. What is potential difference?

3. Define EMF.

4. What is electric resistance?

5. State Ohm’s Law.

6. Tungsten is used in filament in electric bulbs. Give reason.

7. Define watt.

8. What is electrolysis?

9. What is an electrolyte?

10. How can you increase the magnetic effect of current carrying wire?


1. How is lightning useful for plant life?

2. What is the difference between static electricity and electric current?

3. Write the formula for a) Electric current b) Potential difference.

4. Write the formula for a) Resistance b) Electric power.

5. What are the various electrical hazards?

6. Define electric potential.

7. The work done in moving 5 coulombs of charge between two points in an electric field is 30 joules.

Calculate the potential difference between the two points.

8. The potential difference between the ends of a conductor is 40V. If the conductor draws a current of

4A from the source, what current will the conductor draw if the potential difference is increased to

100V?

9.


1. Write the SI unit of a) electric current b) Potential difference c) Resistance

2. Differentiate between conductors, good conductors and super conductors.

3. What is a circuit diagram? Draw a simple circuit diagram.

4. Draw the symbols for the following.

a) An electric cell b) wires crossing without joining c) Plug key d) A wire joint e) a resistor

f) Electric bulb.

5. Three resistors 3 , 4 and 5 are connected in (a) series (b) parallel. Find the equivalent resistance

in each case.

6. Four resistors 6 , 4 and 5 are connected in (a) series (b) parallel. Find the equivalent

resistance in each case.

7. In the circuit diagram calculate the equivalent resistance between a and b.

8. What is a Fuse? What is it made of? Write the property of Fuse wire?

9. What is electroplating? Write its uses?


1. List the factors on which resistance depends on. Explain

2. Differentiate between series and parallel connection.

3. List the types of effects of electric current. Explain

4. List out the various electric safety measures.

5. For the circuit given below calculate the equivalent resistance between the points P and Q.

Lesson – 12

The Sun


1. During solar eclipse we can see the brightest star ______________.

2. The surface temperature of the sun is about ______________.

3. The interior temperature of the sun is about _________________.

4. The nuclear fuel present in the sun is ____________.

5. The innermost layer of the sun is called ______________.

6. The zone that provides an efficient means of transporting energy near the core of the sun is

________.

7. The solar wind consists of ___________.

8. The visible surface of the sun is ___________.

9. Corona of the sun is visible during __________.


1. The mass of the sun is about _____ times the mass of the earth.

a) 3,30,000 b)3,20,000 c) 3,10,000 d)2,30,000

2. The radius of the sun is about _____ times the radius of the earth.

a)108 b)107 c)109 d)106

3. At present 71% of the sun contains _______ gas.

a) hydrogen b) nitrogen c)oxygen d)helium

4. Aurora effect can be demonstrated in the science laboratory also by

a) Producing spectrum

b) Ionizing certain gases by high voltage

c) Using coloured chemicals and their reactions

d) Using coloured glasses and light

5. The colour of the chromosphere is

a) Red b) white c) yellow d) Pink

6. Solar flares are associated with

a) Intense magnetic field

b) Solar eclipse

c) Lunar eclipse

d) Nuclear fission reaction

7. Sun is called the laboratory to study other stars because

a) The sun is a brightest star

b) The sun is nearer to earth

c) Sun is an average star

d) Sun is a medium star.

8. The reason for enormous energy output of the sun is

a) Combustion of hydrogen

b) Formation of helium

c) Combustion of helium

d) Electromagnetic field.

9. Harmful effect of the solar wind on earth is protected by

a) Ozone layer

b) Ionosphere

c) Atmosphere

d) Magnetosphere

10. Sunspots on the photosphere are due to.

a) Eclipses caused by planets

b) Comparatively cooler planets

c) Granulations

d) Cloudy weather on the earth.


1. Imagine that you are standing on the planet Venus and observing the sun. The sun appears to rise in

the west and set in the east. Why?

2. What is Corona?

3. List the activities that take place on the sun’s surface.

4. What is an Aurora?

5. What are Fraunhofer lines?

6. Write the constituents of Sun?

7. State the layers of the earth’s atmosphere which protects us from the radiations of the sun.


1. Explain the two models of our solar system.

2. Presuming that light takes eight minutes to travel from the sun and reach the earth, calculate the

distance of the sun from the earth and express the distance in metres and kilometres.

3. Draw a neat diagram of total solar eclipse showing the corona of the sun.

4. Transition of the planet Venus in the path of the sun and earth. But they are not as spectacular as

eclipse caused by the moon. Why?

5. Differentiate between perihelion and aphelion.


1. List the main features of the sun.

2. Explain the following a) Granulations b) spicules c) chromosphere

3. What are sunspots? To which factors are they related?

4. What is solar wind?

5. State the effects of solar activities.

6. Explain the nuclear reactions that take place in the Sun.

7. State Kepler’s three Laws of motion.


1. Distinguish between solar flares and solar prominences.

2. Explain the structure of the sun with a diagram.

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Lesson 1 HEAT I. - St. Claret School - Physics... · · 2014-11-18Lesson – 1 HEAT I. Fill in the blanks:- ... Metals with different linear expansion coefficient. (b) ... Write