If a constant potential difference is applied across a bulb, the current slightly decreases as time passes and then becomes constant. Explain.

When a potential difference is applied across, the current passing through

If the potential difference applied across a Coolidge tube is increased , then

If the potential difference applied across a Coolidge tube is increased , then

Consider the following quantities: number density of free electrons, n, mean free time of electrons between collisions,t , drift velocity of electrons, v_d , resistivity, p. A constant potential difference is applied across a conductor. Assuming that the temperature of the conductor remains constant, which of these quantities is/are independent of the magnitude of the potential difference applied?

A source of constant potential difference is connected across a conductor having irregular cross section as shown.

A constant potential difference is applied across a metal wire. Let the average thermal velocity of electrons in the wire be v_t and let the drift velocity be v_d . As the temperature of the wire rises:

How does the mobility of electrons in a conductor change, if the potential difference applied across the conductor is doubled, keeping the length and temperature of the conductor constant ?

If the potential difference applied across a variable resistor is constant, draw a graph between the current in the resistor and the resistance.

A constant potential difference is applied across a resistance. Consider variation of resistance with temperature. Which graph represents best the variation of power produced in resistance versus resistance?

If the potential difference across the ends of a conductor is doubled, the current flowing through it gets