Ray Optics and Optical Instruments — Physics STD 12 Science — Question

The particles emitted by radioactive decay are deflected by magnetic field. The particles will be

(a) Protons and α - particles	(b) Electrons, protons and α -particles
(c) Electrons, protons and neutrons	(d) Electrons and α -particles

Wave nature of light follows because

(a) Light rays travel in a straight line

(b) Light exhibits the phenomena of reflection and refraction

(c) Light exhibits the phenomenon of interference

(d) Light causes the phenomenon of photoelectric effect

The three basic properties possessed by the electric charge are:

Photon and electron are given same energy (. Wavelength associated with photon and electron are   and   then correct statement will be

(a)

(b)

(c)

(d)

Two long conductors, separated by a distance d carry current I₁ and I₂ in the same direction. They exert a force F on each other. Now the current in one of them is increased to two times and its directions is reversed. The distance is also increased to 3d. The new value of the force between them is

(a) –2F

(b) F/3

(c) 2F/3

(d) – F/3

The value of resistivity of super conductor is:

A transverse wave travels along the Z-axis. The particles of the medium must move:

1. Along the Z-axis
2. Along the X-axis
3. Along the Y-axis
4. In the X-Y plane.

A charged water drop whose radius is 0.1 μm  is in equilibrium in an electric field. If charge on it is equal to charge of an electron, then intensity of electric field will be (g = 10

(a) 1.61 N/C

(b) 26.2 N/C

(c) 262 N/C

(d) 1610 N/C

The equivalent resistance of the following diagram A and B is

(a)

(b) 9 W

(c) 6 W

(d) None of these

In the following transitions, which one has higher frequency

(a) 3 – 2

(b) 4 – 3

(c) 4 – 2

(d) 3 – 1