Magnetism And Matter — Physics STD 12 Science — Question

For a triode m = 64 and g_m =1600 m mho. It is used as an amplifier and an input signal of 1V (rms) is applied. The signal power in the load of 40 kW will be

(a) 23.5 mW

(b) 48.7 mW

(c) 25.6 mW

(d) None of these

A thin glass (refractive index 1.5) lens has optical power of -5D in air. It's optical power in a liquid medium with refractive index 1.6 will be

(a) 25 D

(b) – 25 D

(c) 1 D

(d) None of these

Coulomb's Law agrees with________?

On rubbing, when one body gets positively charged and other negatively charged, the electrons transferred from positively charged body to negatively charged body are:

A light has amplitude A and angle between analyser and polariser is 60°. Light is reflected by analyser has amplitude

(a) A

(b) A/

(c) A/2

(d) A/2

A conducting gas is in the form of a long cylinder. Current flows through the gas along the length of the cylinder. The current is distributed uniformly across the cross-section of the gas. Disregard thermal and electrostatic forces among the gas molecules. Due to the magnetic fields set up inside the gas and the forces which they exert on the moving ions, the gas will tend to:

The angle between magnetic meridian and geographical meridian is called :

Two charged spheres separated at a distance d exert a force F on each other. If they are immersed in a liquid of dielectric constant 2, then what is the force (if all conditions are same)

(a)

(b) F

(c) 2F

(d) 4F

Compton effect is associated with

(a) α -  rays

(b) β -  rays

(c) X-rays

(d) Positive rays

The magnitude of i in ampere unit is

(a) 0.1

(b) 0.3

(c) 0.6

(d) None of these