Electrostatics

Two-point charges +4 mC and -1mC are separated by a distance of d. The ratio of force acting on them will be

• 4:1

• 1:4

• 1:1

• 1:16

A charge of 2 x 10^-7C is acted upon by a force of 0.1N. Determine the distance to other charges of 4.5 x 10^-7 C, both the charges are in a vacuum.

• 0.03 m

• 0.05 m

• 0.07 m

• 0.09 m

A soap bubble is given a negative charge, then its radius

• Decreases

• Increases

• Remains same

• none of these

Two charges are placed at a certain distance. If the magnitude of each charge is doubled & the distance between is them is halved, the force will become

• 4 times its original value

• 8 times its original value

• 16 times of its original value

• remains same

If a body has a positive charge of 10^-12 coulomb

• The body has a 6.25x 10^6 deficiency of electrons

• The body has 625x 10^6 excess electrons

• The body has 6.25x 10^3 deficiency of electrons

• The body has 6.25x 10^6 excess electrons

Two-point charges -2Q and +Q are situated as shown in the figure. At which point could the resultant electric field due to these charges be zero

• A

• B

• C

• D

In the last question if the distance between the charges is 1 m, then find the zero-field location.

• 2 m

• 2.5 m

• 0.5 m

• 0.25 m

The gold nucleus is represented by the symbol 197Au79 taking as the elementary charge. What is the electric field strength at the surface of gold?

• Zero

• 79e/4πε r^2

• 197e/4πε r^2

• 79e^2/4πε r^2

Equal charges are given to two spheres of different radii. The potential will

• be more on the smaller sphere

• be more on the bigger sphere

• be equal on both the spheres

• Depend on the nature of the materials of the spheres

The figure shows some of the electric field lines corresponding to an electric field. The figure suggests

• EA>EB>EC

• EA=EB=EC

• EA=EC>EB

• EA=EC<EB