Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

Identify the simplest and the most widely used capacitor among the following.

The dimensions of dipole moment are:

What is the purpose of filament in electron gun inside a cathode ray tube?

Ohm's law is true

(a) For metallic conductors at low temperature

(b) For metallic conductors at high temperature

(c) For electrolytes when current passes through them

(d) For diode when current flows

Two parallel wires of length 9 m each are separated by a distance 0.15 m. If they carry equal currents in the same direction and exerts a total force of 30 × 10^–7 N on each other, then the value of current must be

(a) 2.5 amp

(b) 3.5 amp

(c) 1.5 amp

(d) 0.5 amp

Vibration magnetometer is used for comparing

(a) Magnetic fields

(b) Earth's field

(c) Magnetic moments

(d) All of the above

Zener diode acts as a/an:

The mechanism of the heat produced in a conductor when an electric current flows through it, can be explained on the basis of

(a) Viscosity

(b) Friction

(c) Free electron theory

(d) Gauss's theorem

The example of nuclear fusion is

(a) Formation of Ba and Kr from U235

(b) Formation of He from H

(c) Formation of Pu – 235 from U - 235

(d) Formation of water from hydrogen and oxygen

Which is the best conductor of electricity?