Physics - Study Mode

[#866] Suppose voltage V is applied across a resistance R. The power dissipated in the resistance is P. Now the same voltage V is applied across a parallel combination of three equal resistors each of resistance R. Then the power dissipated in the second case will be
Correct Answer

(B) 3P

Explanation

Solution: P = I 2 R where, I = Current, P = Electric Power, R = Resistance. Here all the resistance is put in parallel combination and in parallel combination the value of Resistance decreases and dissipation of power increase, hence 3 times more power will be dissipated(3P).

[#867] A galvanometer can be converted into a voltmeter by connecting with it a
Correct Answer

(C) High resistance on series

Explanation

Solution: A galvanometer is converted into a voltmeter by connecting with high resistance.

[#868] In superconductors, the energy gap is due to
Correct Answer

(B) Electron-phonon interaction

Explanation

Solution: In superconductors, the energy gap is due to electron-phonon interaction.

[#869] Electrical Pressure is also called
Correct Answer

(B) Voltage

Explanation

Solution: A unit of electrical pressure (or electromotive force) which causes current to flow in a circuit is called voltage. One volt is the amount of pressure required to cause one ampere of current to flow against one ohm of resistance.

[#870] The ''Choke' used with a tube light is basically
Correct Answer

(A) An inductor

Explanation

Solution: Choke is the Inductor coil/ballast which is used to induce high voltage across it. Then gas inside the starter gets ionized due to this full voltage and heats the bimetallic strip that is caused to be bent to connect to the fixed contact.