Moving Charges and Magnetism — Physics STD 12 Science — Question

In a charged capacitor, the energy resides

(a) The positive charges	(b) Both the positive and negative charges
(c) The field between the plates	(d) Around the edge of the capacitor plates

Advantage of optical fibre

(a) High bandwidth and EM interference

(b) Low bandwidth and EM interference

(c) High band width, low transmission capacity and no EM interference

(d) High bandwidth, high data transmission capacity and no EM interference

Which of the following could not produce a virtual image

(a) Plane mirror

(b) Convex mirror

(c) Concave mirror

(d) All the above can produce a virtual image

The resistivity of a wire varies with:

The electric field in a region is directed outward and is proportional to the distance r from the origin. Taking the electric potential at the origin to be zero,

1. It is uniform in the region.
2. It is proportional to r.
3. It is proportional to r².
4. It increases as one goes away from the origin.

A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to the one of the sides of the loop and is in the plane of the loop. If a steady current I is established in wire as shown in figure, the loop will

(a) Rotate about an axis parallel to the wire

(b) Move away from the wire or towards right

(c) Move towards the wire

(d) Remain stationary

If frequency of the incident photon on the metal surface is made double, then kinetic energy of the emitted photoelectron will become :

Two thin wire rings each having a radius R are placed at  a distance d apart with their axes coinciding. The charges on the two rings are +q  and -q. The potential difference between the centres of the two rings is

(a) Zero	(b)
(c)	(d)

When _15​P³⁰ decays to become _14​Si³⁰, which particle is released?

Fusion reaction take place at high temperature because: