Current Electricity

The mobility of charge carriers is defined as the drift velocity per unit electric field. Its SI unit is:

Which of the following physical quantities represents the slope of the Voltage ($V$) vs Current ($I$) graph for an Ohmic conductor?

The relaxation time ($\tau$) of electrons in a metal is a function of temperature. If the temperature of a conductor increases, the relaxation time:

The relaxation time ($\\tau$) in a conductor:

Which of the following describes the microscopic form of Ohm's Law?

A wire of length $L$ and resistance $R$ is stretched to triple its original length while keeping its volume constant. How does the resistivity of the wire change?

While applying Kirchhoff's Loop Rule, if we travel through a resistor of resistance $R$ in the same direction as the current $I$, the change in potential is taken as:

Consider the junction shown in the diagram. If the currents entering and leaving the junction are as labeled, what is the value of the unknown current $I$?

Kirchhoff's second law, known as the loop rule ($\sum \Delta V = 0$), is based on the law of conservation of:

In the circuit shown below, the galvanometer $G$ shows zero deflection. What is the value of the unknown resistance $X$ if $P = 10 \Omega$, $Q = 100 \Omega$, and $R = 40 \Omega$?

Which of the following physical quantities is kept constant throughout the wire of a Meter Bridge to ensure accurate results?

Under what condition is a Wheatstone bridge considered most sensitive?

The principle of a potentiometer states that the potential drop across any portion of the wire is directly proportional to the length of that portion, provided that:

To increase the sensitivity of a potentiometer, which of the following actions should be taken?

The internal resistance $r$ of a cell of EMF $E$ and terminal voltage $V$ connected across an external resistance $R$ is given by which of the following expressions?