What does a rheostat control?

What does Rheostat controls? electron drift velocity or quantity of electrons? We know I=nAve I=current n=quantity of electron A=conductor area e=electron charge v=drift velocity (Asked  Partha)

Random collection of Physics Viva Questions

State the Principle of a potentiometer. (The students say that potential drop is proportional to length but the constant quantities are not mentioned) How can we increase the sensitivity of a potentiometer? Define figure of merit of a galvanometer. Which has more resistance – a galvanometer or a milliammeter? How does an LED emit light? … Continue reading Random collection of Physics Viva Questions

Why direct currents aren’t used in Home circuits?

How can an alternating current change its direction while moving in a wire or any conductor? Why direct currents aren’t used in Home circuits? RAHUL ASKED Answer: Alternating current is produced by rotating a coil in a strong magnetic field (or ...