# Photon Academy Of Science 04 (Unit 1 Whole)

31 Questions | Total Attempts: 148  Settings  .

• 1.
An electric dipole is placed at an angle of 30° with an electric field intensity 2 × 105 N/C. It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is [NEET 2016]
• A.

8mC

• B.

2mC

• C.

5mC

• D.

7mC

• 2.
A combination of capacitors is set up as shown in the figure. The magnitude of the electric field, due to a point charge Q (having a charge equal to the sum of the charges on the 4 μF and 9 μF capacitors), at a point distant 30 m from it, would equal : [JEE Main 2016]
• A.

360N/C

• B.

420N/C

• C.

480N/C

• D.

240N/C

• 3.
Aand are three points in a uniform electric field. The electric potential is [NEET 2013]
• A.

At A

• B.

At B

• C.

At C

• D.

At all A B and C

• 4.
Three concentric metallic spherical shells of radii R, 2R, 3R, are given charges Q1, Q2, Q3, respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells, Q1 : Q2 : Q3, is [IIT JEE 2009]
• A.

1 : 2 : 3

• B.

1:3:5

• C.

1:4:9

• D.

1:8:18

• 5.
If the static electric force is 144 N, what is the distance between both charges… (1μC = 10-6 C and k = 9.109 N.m2.C-2)
• A.

5cm

• B.

4cm

• C.

3cm

• D.

9cm

• 6.
The force between two charges is 120 N. If the distance between the charges is doubled, the force will be
• A.

30N

• B.

20N

• C.

40N

• D.

240N

• 7.
The electric field intensity at a point situated 4 meters from a point charge is 200 N/C. If the distance is reduced to 2 meters, the field intensity will be
• A.

800N/C

• B.

400N/c

• C.

200N/C

• D.

100N/c

• 8.
A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is
• A.

0.024f

• B.

24f

• C.

240f

• D.

0.240f

• 9.
What is si unit of capacitance
• A.

• B.

C/v

• C.

N/c

• D.

Ohm

• 10.
What is the value of flux for one face of cube
• A.

Φ=q/£•

• B.

1/6 q/£•

• C.

Q/l

• D.

Side x side

• 11.
Coulomb's force between 2 point charges 10µC and 5µC placed at a distance of 150cm is
• A.

0.2N

• B.

0.5N

• C.

5N

• D.

4N

• 12.
If 2 bodies are oppositely charged with 400µC and 200µC, distance between them in air is 0.5 m. force between bodies should be
• A.

2880N

• B.

2800N

• C.

1300N

• D.

1440N

• 13.
What would be energy supplied by charge if a point charge of +2 is transferred from a point at potential 100V to a point at potential 50V?
• A.

100J

• B.

10J

• C.

1000J

• D.

0J

• 14.
Amount of work done in bringing a unit positive charge from infinity to point in an electric field is termed as
• A.

Potential

• B.

Electric field

• C.

Electric dipole

• D.

Electric flux

• 15.
A dielectric K = 2 is inserted between the plates of a 20μF capacitor. It capacitance will become  In
• A.

20μF

• B.

40

• C.

60

• D.

10

• 16.
One Joule per coulomb is called?
• A.

Volt

• B.

Newton

• C.

• D.

Ohm

• 17.
If two capacitors of lOμF each are connected in parallel, their equivalent capacitance will be?
• A.

• B.

• C.

• D.

• 18.
In domestic wiring we use which type of combination
• A.

Paralle

• B.

Series

• C.

Mixed

• D.

Simple

• 19.
A dielectric slab which is responsible for increasing capacitance is
• A.

Polar

• B.

Non polar

• C.

Both polar and non polar

• D.

Insulator

• 20.
Calculate the equivalent capacitance between the points a and b.
• A.

3c/4

• B.

4/3c

• C.

C/4

• D.

3c

• 21.
Electric charge q , q and -2q are placed at the corners of an equilateral triangle ABC of side L. The magnitude of electric dipole moment of the system is
• A.

(√3)qL

• B.

Ql

• C.

2qL

• D.

5qL

• 22.
If positively charged pendulum is oscillating in a uniform electric field as shown in figure. Its time period as compared to that when it was uncharged:
• A.

Will increase

• B.

No change

• C.

Will decrease

• D.

Will doubled

• 23.
The figure is a plot of lines of force due to two charges q1 and q2. Find out the sign of charges
• A.

Both are positive

• B.

Both are negative

• C.

Both are neutral for each other

• D.

Can't expressable

• 24.
In the electric field due to a point charge q, a test charge is carried from A to the points B, C, D and E lying on the same circle around q. The work done is
• A.

Zero along any one of the paths AB, AD, AC and AE

• B.

Least along AB

• C.

Least along  BC

• D.

Least along AE

• 25.
A charge ‘Q’ is placed at the centre of a hemispherical surface of radius ‘R’. The flux of electric field due to charge ‘Q’, through the surface of hemisphere is
• A.

Q/2εo

• B.

I/2q

• C.

Q/4εo

• D.

2Q/εo Back to top