This document consists of 3 printed pages.

19 M

:........................................................ Code: 9702 Class: AI

Test (Unit 1)

40M

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heory Section:

T [Total arks]

Time Allowed: inutes

Maximum Marks: 25

NIQUE SCIENCE ACADEMY U

Date

Name

Paper: Physics

1

Dedicated to My Son Mohammad Irtaza Zain. Code 9702

1 Make reasonable estimates of the following quantities.

(a) mass of an apple

mass = ............................................... kg [1]

(b) number of joules of energy in 1 kilowatt-hour

number = ................................................... [1]

(c) wavelength of red light in a vacuum

wavelength = ............................................... m [1]

(d) pressure due to a depth of 10 m of water

pressure = .............................................. Pa [1]

[Total 4]2 (a) Derive the SI base unit of force.

SI base unit of force = ………………………………… [1]

(b) A spherical ball of radius r experiences a resistive force F due to the air as it movesthrough the air at speed v. The resistive force F is given by the expression

F = crv,

where c is a constant.

Derive the SI base unit of the constant c.

SI base unit of c = ………………………………… [1]

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Dedicated to My Son Mohammad Irtaza Zain. Code 9702

(c) The ball is dropped from rest through a height of 4.5 m.

(i) Assuming air resistance to be negligible, calculate the final speed of the ball.

speed = …………………………… m s–1 [2]

(ii) The ball has mass 15 g and radius 1.2 cm.

The numerical value of the constant c in the equation in (b) is equal to 3.2 × 10–4

when measured using the SI system of units.

Show quantitatively whether the assumption made in (i) is justified.

[3][Total 7]

2 (a) Two of the SI base quantities and their units are mass (kg) and length (m).

Name three other SI base quantities and their units.

1. quantity ....................................................... unit .........................................................

2. quantity ....................................................... unit .........................................................

3. quantity ....................................................... unit .........................................................[3]

(b) The pressure p due to a liquid of density ρ is related to the depth h by the expression

p = ρgh,

where g is the acceleration of free fall.

Use this expression to determine the derived units of pressure. Explain your working.

[5]

[Total 8]

3

Dedicated to My Son Mohammad Irtaza Zain. Code 9702

6 MCQ SECTION: [Total Marks] 1 Which of the following pairs of units are both SI base units?

A ampere, degree celsius

B ampere, kelvin

C coulomb, degree celsius

D coulomb, kelvin

2 What is a possible unit for the product VI, where V is the potential difference across a resistor

and I is the current through the same resistor?

A newton per second (Ns–1)

B newton second (Ns)

C newton metre (Nm)

D newton metre per second (Nm s–1)

3 What is the unit watt in terms of SI base units?

A J s–1 B m2 kgs–1 C m2 kgs–3 D Nms–1

4 The SI unit for potential difference (the volt) is given, in base units, by

A kg mA–1 s–3.

B m2 A–1 s–2.

C kgm2 s–2.

D kgm2 A–1 s–3.

5 The product of pressure and volume has the same SI base units as

A energy.

B force.

Carea

force .

Dlength

force .

6 Which definition is correct and uses only quantities rather than units?

A Density is mass per cubic metre.

B Potential difference is energy per unit current.

C Pressure is force per unit area.

D Speed is distance travelled per second.

6 A B C D

5 A B C D

4 A B C D

3 A B C D

2 A B C D

1 A B C D

MCQ Answer Sheet