# 12 - Physics - Unit 1 - Electro Statics

15 Questions | Attempts: 13641
Share

Settings

Prepared by Mr. P. ILAIYARAJA M. Sc. ,B. Ed. , PG ASST IN PHYSICS , GHSS, PANCHANATHIKKULAM EAST, NAGAI DT.   ; & www. Padasalai. Net

• 1.
The electrostatic force between two point charges kept at a distance d apart, in a medium εr = 6, is 0.3 N. The force between them at the same separation in vacuum is
• A.

1.8 N

• B.

0.5 N

• C.

20 N

• D.

2 N

• 2.
Elecric field intensity is 400 V m1 at a distance of 2 m from a point charge. It will be 100 V m1 at a distance?
• A.

4 m

• B.

4 cm

• C.

1.5 m

• D.

50 cm

• 3.
Two point charges +4q and +q are placed 30 cm apart. At what point on the line joining them the electric field is zero?
• A.

20 cm from the charge 4q

• B.

15 cm from the charge q

• C.

7.5 cm from the charge q

• D.

5 cm from the charge q

• 4.
A dipole is placed in a uniform electric field with its axis parallel to the field. It experiences
• A.

Neither a net force nor a torque

• B.

Only a torque

• C.

Both a net force and torque

• D.

Only a net force

• 5.
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

• 6.
Which of the following quantities is scalar?
• A.

Electric potential

• B.

Electric force

• C.

Electric field

• D.

Dipole moment

• 7.
The capacitance of a parallel plate capacitor increases from 5 μf to 60 μf when a dielectric is filled between the plates. The dielectric constant of the dielectric is
• A.

12

• B.

55

• C.

65

• D.

10

• 8.
A hollow metal ball carrying an electric charge produces no electric field at points
• A.

Inside the sphere

• B.

On its surface

• C.

Outside the sphere

• D.

At a distance more than twice

• 9.
A glass rod rubbed with silk acquires a charge of  . The number of electrons it has gained or lost (1) (gained)                                   (2) (lost) (3) (lost)                                        (4) (lost)
• A.

(2)

• B.

(1)

• C.

(4)

• D.

(3)

• 10.
If a point lies at a distance x from the midpoint of the dipole, the electric potential at this point is proportional to (1)        (2)            (3)                (4)
• A.

(1)

• B.

(2)

• C.

(3)

• D.

(4)

• 11.
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 center O of the square is (1)     (2)         (3)            (4) zero
• A.

(4)

• B.

(3)

• C.

(2)

• D.

(1)

• 12.
Electric potential energy (U) of two point charges is (1)            (2)        (3) pE cos θ            (4) pE sin θ
• A.

(2)

• B.

(3)

• C.

(1)

• D.

(4)

• 13.
The unit of permittivity is  (1) C2 N1 m2                    (2) N m2 C2       (3) H m1           (4) N C2 m2
• A.

(1)

• B.

(2)

• C.

(3)

• D.

(4)

• 14.
The number of electric lines of force originating from a charge of 1 C is (1)     (2)    (3)      (4)
• A.

(1)

• B.

(2)

• C.

(3)

• D.

(4)

• 15.
The electric field outside the plates of two oppositely charged plane sheets of charge density σ is (1)        (2)            (3)            (4) zero
• A.

(4)

• B.

(3)

• C.

(2)

• D.

(1)