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

The fact that photons carry energy was established by

(a) Doppler's effect	(b) Compton's effect
(c) Bohr's theory	(d) Diffraction of light

Gauss’s law should be invalid if

(a) There were magnetic monopoles

(b) The inverse square law were not exactly true

(c) The velocity of light were not a universal constant

(d) None of these

50% of the X-ray coming from a Coolidge tube is able to pass through a 0.1mm thick aluminium foil. The potential difference between the target and the filament is increased. The thickness of the aluminium foil that will allow 50% of the X-ray to pass through will be:

1. zero
2. < 0.1mm
3. 0.1mm
4. > 0.1mm

An electron (charge = 1.6 ) is accelerated through a potential of 100,000 V. The energy acquired by the electron is

(a) 1.6

(b) 1.6

(c) 0.53

(d) 1.6

In an electrical circuit, which of the following quantities is analogous to temperature?

Consider the situation shown in figure. The straight wire is fixed but the loop can move under magnetic force. The loop will:

1. Remain stationary.
2. Move towards the wire.
3. Move away from the wire.
4. Rotate about the wire.

There are two charges +1 microcoulombs and +5 microcoulombs. The ratio of the forces acting on them will be

(a) 1 : 5

(b) 1 : 1

(c) 5 : 1

(d) 1 : 25

What is the order of the radius of an electron orbit in a hydrogen atom?

For which nucleus will the value of binding energy per nucleon be maximum?

Two particles each of mass m and charge q are attached to the two ends of a light rigid rod of length 2R. The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod is

(a)

(b)

(c)

(d)