CBSE
Multiple Choice QuestionsA hexagon of side 8 cm has a charge 4 µC at each of its vertices. The potential at the centre of the hexagon is
2.7 × 106 V
7.2 × 1011 V
2.5 × 1012 V
3.4 × 104 V
Two charged spheres separated by a distance 'd' exert some force on each other. If they are immersed in a liquid of dielectric constant 2, then what is the force exerted, if all other conditions are same?
F/2
F
2F
4F
A 5 µF capacitor is charged by being connected to a 3 V battery. The battery is then disconnected. If the resistance of the dielectric material between the capacitor plates is 109 Ω, what is the charge remaining on the capacitor 1 h after it has been disconnected ?
1.5 × 10-5 C
7.4 × 10-6 C
5.4 × 10-6 C
8.4 × 10-5 C
Assertion: On going away from a point charge or a small electric dipole, electric field decreases at the same rate in both the cases.
Reason: Electric field is inversely proportional to square of distance from the charge or on electric dipole.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
if both assertion and reason are false.
2, 4 and 6 S are the conductances of three conductors. When they are joined in parallel, their equivalent conductance will be
12 S
( 1/12 ) S
( 12 /11 ) S
11/12 S
A metallic solid sphere is placed in a uniform electric field. Which path, the lines of force follow as shown in figure?
1
2
3
4
Assertion: If a conductor is given charge then no excess inner charge appears.
Reason: Electric field inside conductor is zero.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
The diameter of the plate of a parallel plate condenser is 6 cm. If its capacity is equal to that of a sphere of diameter 200 cm, the separation between the plates of the condenser is
4·5 × 10-4 m
2·25 × 10-4 m
6·75 × 10-4 m
9 × 10-4 m
Assertion: Gaussian surface is considered carefully.
Reason: The point where electric field to be calculated should be with in the surface
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
In a uniform electric field a charge of 3 C experiences a force of 3000 N. The potential difference between two points 1 cm apart along the electric line of force will be
10 V
30 V
300 V
100 V
