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

The coil of area 0.1 m² has 500 turns. After placing the coil in a magnetic field of strength 4, if rotated through 90^o in 0.1 s, the average emf induced in the coil is

(a) 0.012 V

(b) 0.05 V

(c) 0.1 V

(d) 0.2 V

An electric fan and a heater are marked as 100 watt, 220 volt and 1000 watt, 220 volt respectively. The resistance of the heater is

(a) Zero	(b) Greater than that of the fan
(c) Less than that of the fan	(d) Equal to that of the fan

Kilowatt hour is the unit of :

An electron is accelerated through a p.d. of 45.5 volt. The velocity acquired by it is (in ms^-1)

(a) 4

(b) 4

(c)

(d) Zero

For nuclei with A > 100:

1. The binding energy of the nucleus decreases on an average as A increases.
2. The binding energy per nucleon decreases on an average as A increases.
3. If the nucleus breaks into two roughly equal parts, energy is released.
4. If two nuclei fuse to form a bigger nucleus, energy is released.

Assertion :   Penetrating power of X-rays increases with the increasing the wavelength.

Reason    : The penetrating power of X-rays increases with the frequency of X-rays.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If assertion is false but reason is true.

Nuclear force is :

In the adjoining diagram, a wavefront AB, moving in air is incident on a plane glass surface XY. Its position CD after refraction through a glass slab is shown also along with the normals drawn at A and D. The refractive index of glass with respect to air (μ = 1) will be equal to

(a)

(b)

(c)

(d)

Magnetic field at the centre of a circular coil of radius r, through which a current I flows is:

The ratio of the refractive index of red light to blue light in air is

(a) Less than unity

(b) Equal to unity

(c) Greater than unity

(d) Less as well as greater than unity depending upon the experimental arrangement