# Physics Test: Important Practice Questions On Electrostatics!

10 Questions | Total Attempts: 846  Settings  .

• 1.
A glass rod rubbed with silk acquires a charge of +8 x 10-12C. The number of electrons it has gained or lost
• A.

5 x 10-7(gained)

• B.

5 x 107(lost)

• C.

2 x 10-8(lost)

• D.

-8 x 10-12(lost)

• 2.
The electrostatic force between two point charges kept at a distance  d apart , in a medium εr =6, is 0.3N. The force between them at the same separation in vacuum is
• A.

20 N

• B.

0.5 N

• C.

1.8 N

• D.

2 N

• 3.
Electric field intensity is 400Vm-1 at a distance of 2m from a point charge.It will be 100Vm-1 at a distance?
• A.

50 cm

• B.

4 cm

• C.

4 m

• D.

1.5 m

• 4.
Two point charges +4q and +q are placed 30cm apart. At what point on the line joining them the electric field is zero?
• A.

15 cm from the charge q

• B.

7.5 cm from the charge q

• C.

20 cm from the charge 4q

• D.

5 cm from the charge q

• 5.
A dipole is placed in a uniform electric field with its axis parallel to the field. It experiences
• A.

Only a net force

• B.

Only a torque

• C.

Both a net force and torque

• D.

Neither a net force nor a torque

• 6.
If a point lies at a distance x from the midpoint of the dipole, the electric potential at this point is proportional to
• A.

1/x2

• B.

1/x3

• C.

1/x4

• D.

1/x3/2

• 7.
Four charges +q, +q, -q and -q respectively are placed at the corners A,B,C and D of a square of side a. The electric potential at the centre O of the square is
• A.

Q/4πεoa

• B.

2q/4πεoa

• C.

4q/4πεoa

• D.

Zero

• 8.
Electric potential energy (U) of two point charges is
• A.

Q1q2/4πεor2

• B.

Q1q2/4πεor

• C.

PE cosθ

• D.

PE sinθ

• 9.
The work done in moving 500 μC charge between two points on equipotential surface is
• A.

Zero

• B.

Finite positive

• C.

Finite negative

• D.

Infinite

• 10.
Which of the following quantities is scalar?
• A.

Dipole moment

• B.

Electric force

• C.

Electric field

• D.

Electric potential

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