Electric force and field problem set

Problem Set: Electric Force and Field

1. A positively charged rod is brought close to a neutral piece of paper,which it attracts. Draw a diagram showing the separation of chargeand explain why attraction occurs.

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2. The form of Coulomb’s law is very similar to that for Newton’s lawof universal gravitation. What are the differences between these twolaws? Compare also gravitational mass and electric charge.

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3. Explain why the test charges we use when measuring electric fieldsmust be small.

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4. Draw the electric field lines surrounding two negative electric chargesa distance l apart.

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5. Why can’t electric field lines cross?

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Mrs. Kate Rimando IB Physics 11 SY 2010-2011

Problem Set: Electric Force and Field

6. Three positive particles of equal charge +11.0µC, are located at thecorners of an equilateral triangle of side 15.0cm. Calculate themagnitude and direction of the net force on each particle.

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7. Calculate the electric field at one corner of a square 52.5cm on a sideif one corner is occupied by a +45.0µC charge and the other threeare occupied by −27µC charges.

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Mrs. Kate Rimando IB Physics 11 SY 2010-2011