Revise smart, understand Better

5/30 MCQs for:

Electric fields

Two 0.20-g metal spheres are hung from a common point by non-conducting threads which are 30 cm long. Both are given identical charges, and the electrostatic repulsion forces them apart until the angle between the threads is 200. How much charge was placed on each sphere?

10 nC.

15 nC

20 nC.

25 nC.

Can electric field lines intersect in free space?

No.

Yes, but only at the midpoint between a positive and a negative charge.

Yes, but only at the centroid of an equilateral triangle with like charges at each corner.

Yes, but only at the midpoint between two equal like charges.

Consider point charges of +Q and +4Q, which are separated by 3.0 m. At what point, on a line between the two charges, would it be possible to place a charge of -Q such that the electrostatic force acting on it would be zero?

1.0 m from the +4Q charge.

There is no such point possible.

1.0 m from the +Q charge.

0.60 m from the +Q charge.

Two charged objects are separated by a distance d. The first charge is larger in magnitude than the second charge.

The charges exert forces on each other equal in magnitude and pointing in the same direction.

The charges exert forces on each other equal in magnitude and opposite in direction.

The first charge exerts a larger force on the second charge.

The second charge exerts a larger force on the first charge.

A large negatively charged object is placed on an insulated table. A neutral metallic ball rolls straight toward the object, but stops before it touches it. A second neutral metallic ball rolls along the path followed by the first ball, strikes the first ball, and stops. The first ball rolls forward, but does not touch the negative object. At no time does either ball touch the negative object. What is the final charge on each ball?

The first ball is positive, and the second ball is negative.

The first ball is negative, and the second ball is positive.

Both balls remain neutral.

Both balls are positive.