Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

A circular current carrying coil has a radius R. The distance from the centre of the coil on the axis where the magnetic induction will be   to its value at the centre of the coil, is

(a)

(b) R

(c) 2

(d)

Pick out the material that cannot be used to make permanent magnets.

Two spheres of radius a and b respectively are charged and joined by a wire. The ratio of electric field of the spheres is

(a) a/b

(b) b/a

(c)

(d)

Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s . If an average emf of 100 V induced then the value of self inductance of the circuit is ___________ .

Energy bands in solids are a consequence of

(a) Ohm’s Law	(b) Pauli’s exclusion principle
(c) Bohr’s theory	(d) Heisenberg’s uncertainty principle

There is some liquid in a closed bottle. The amount of liquid remains constant as time passes. The vapour in the remaining part:

1. Must be saturated.
2. Must be unsaturated.
3. May be unsaturated.
4. There will be no vapour.

Tesla is a unit of:

There exists an electric field of 1N/C along Y direction. The flux passing through the square of 1m placed in XY plane inside the electric field is?

An electron jumps from the 4^th orbit to the 2^nd orbit of hydrogen atom. Given the Rydberg's constant  . The frequency in Hz of the emitted radiation will be

(a)

(b)

(c)

(d)

The potential difference between the two plates of a parallel plate capacitor is constant. When air between the plates is replaced by dielectric material, the electric field intensity: