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

In a diffraction pattern by a wire, on increasing diameter of wire, fringe width

(a) Decreases

(b) Increases

(c) Remains unchanged

(d) Increasing or decreasing will depend on wavelength

A heavy stone is thrown in from a cliff of height h in a given direction. The speed with which it hits the ground:

1. Must depend on the speed of projection.
2. Must be larger than the speed of projectio.
3. Must be independent of the speed of projection.
4. May be smaller than the speed of projection.

Magnetic flux in a circuit containing a coil of resistance 2Ω changes from 2.0 Wb to 10 Wb in 0.2 sec. The charge passed through the coil in this time is

(a) 0.8 C

(b) 1.0 C

(c) 5.0 C

(d) 4.0 C

There are seven orbitals in a subshell then the value of l for it will be:

 and  represents gravitational and electrostatic force respectively between electrons situated at a distance 10 cm. The ratio of  is of the order of

(a)

(b) 10

(c) 1

(d)

The colour of sky is blue due to :

Which of the following properties show that light is a transverse wave?

If m is mass of electron, v its velocity, r the radius of stationary circular orbit around a nucleus with charge Ze, then from Bohr's first postulate, the kinetic energy K =  of the electron in C.G.S. system is equal to

(a)

(b)

(c)

(d)

A magnet is brought towards a coil (i) speedly (ii) slowly then the induced e.m.f./induced charge will be respectively

(a)  More in first case / More in first case

(b)  More in first case/Equal in both case

(c)  Less in first case/More in second case

(d)  Less in first case/Equal in both case