Magnetism — Physics STD 12 Science — Question

The dual nature of light is exhibited by(a) Photoelectric effect(b) Refraction and interference(c) Diffraction and reflection(d) Diffraction and photoelectric effect

Consider a sample of a pure beta-active material:

1. All the beta particles emitted have the same energy.
2. The beta particles originally exist inside the nucleus and are ejected at the time of beta decay.
3. The antineutrino emitted in a beta decay has zero mass and hence zero momentum.
4. The active nucleus changes to one of its isobars after the beta decay.

The outer sphere of a spherical air capacitor is earthed. For increasing its capacitance(a) Vacuum is created between two spheres(b) Dielectric material is filled between the two spheres(c) The space between two spheres is increased(d) The earthing of the outer sphere is removed

In a thermocouple, the temperature that does not depend on the temperature of the cold junction is called(a) Neutral temperature(b) Temperature of inversion(c) Both the above(d) None of the above

What determines the hardness of the X-rays obtained from the Coolige tube(a) Current in the filament(b) Pressure of air in the tube(c) Nature of target(d) Potential difference between cathode and target

The process of adding impurities to the pure semiconductor is called(a) Drouping(b) Drooping(c) Doping(d) None of these

The period of oscillations of a magnet is 2 sec. When it is remagnetised so that the pole strength is 4 times its period will be(a) 4 sec               (b) 2 sec(c) 1 sec  (d) 1/2 sec

Electric current is due to drift of electrons in: