Nuclei — Physics STD 12 Science — Question

The variation of induced emf (E) with time (t) in a coil if a short bar magnet is moved along its axis with a constant velocity is best represented as

(a)

(b)

(c)

(d)

n identical bulbs, each designed to draw a power p from a certain voltage supply, are joined in series across that supply. The total power which they will draw is

(a)

(b) p/n

(c) p

(d) np

Cathode rays are similar to visible light rays in that

(a) They both can be deflected by electric and magnetic fields

(b) They both have a definite magnitude of wavelength

(b) They both have a definite magnitude of wavelength

(d) They both can expose a photographic plate

If the light moving in a straight line bends by a small but fixed angle, it may be a case of:

1. Reflection.
2. Refraction.
3. Diffraction.
4. Dispersion.

Current density is a __________.

Which of the following is not an application of eddy currents

(a) Induction furnace	(b) Galvanometer damping
(c) Speedometer of automobiles	(d) X-ray crystallography

Two charges are placed a certain distance apart in air. If a brass plate is introduced between them, the force between them will:

Equivalent capacitance between A and B is

(a) 8 μC

(b) 6 μF

(c) 26 μF

(d) 10/3 μF

The nucleus   splits exactly in half in a fission reaction in which two neutrons are released. The resultant nuclei are

(a)

(b)

(c)

(d)

The positive temperature coefficient of resistance is for

(a) Carbon

(b) Germanium

(c) Copper

(d) An electrolyte