Current Electricity

Which of the following is true for a conductor in electrostatic equilibrium (no current)?

The drift velocity of electrons depends on:

What is the SI unit of relaxation time?

For a constant current, the drift velocity $v_d$ is proportional to:

The acceleration of free electrons in a conductor exists only:

A potential difference $V$ is applied across a wire. If the temperature of the wire is increased, what happens to the current $I$ and drift velocity $v_d$?

The ratio of the drift velocity to the thermal velocity of electrons at room temperature is approximately:

Which of the following describes the behavior of charge carriers in a liquid electrolyte compared to a solid metal conductor?

A potential difference $V$ is applied across a copper wire of length $L$ and diameter $d$. If $d$ is doubled, how does the drift velocity $v_d$ change?

What is the physical significance of the area under the velocity-time graph of a single electron between two collisions?

Which conservation law forms the basis of Kirchhoff's Second Law (Loop Rule)?

In the given junction of a circuit, what is the value of the unknown current $I$ based on Kirchhoff's First Law?

In a closed loop, if we move in the direction of the current, the change in potential across a resistor $R$ is:

The potential gradient of a potentiometer wire is defined as:

For the given network, apply Kirchhoff's Voltage Law (KVL) to find the potential difference across the $5 \Omega$ resistor.

The internal resistance of a cell of EMF $2V$ is $0.1\Omega$. It is connected to a resistance of $3.9\Omega$. The terminal voltage of the cell will be:

If the current through a $12\Omega$ resistor is $2A$ and the current through a parallel $6\Omega$ resistor is $4A$, what is the total current entering the junction?

In a conversion of a galvanometer into a voltmeter, a resistance of $4950 \Omega$ is connected in series with a galvanometer of resistance $50 \Omega$ to read up to $10V$. If the same galvanometer is to be converted into an ammeter to read up to $2A$, what is the required shunt resistance?

An engineer designs a multi-loop DC circuit. Applying Kirchhoff's rules, find the current flowing through the central $5 \Omega$ resistor in the network where $V_1=20V$, $V_2=10V$, $R_1=2 \Omega$, $R_2=4 \Omega$, and the central branch has $R_3=5 \Omega$.

Two batteries of emfs $E_1 = 12V$ and $E_2 = 8V$ with internal resistances $r_1 = 1 \Omega$ and $r_2 = 2 \Omega$ respectively are connected in parallel to an external load of $10 \Omega$. Using Kirchhoff's laws, determine the power dissipated in the internal resistance of the second battery ($r_2$).

Which material is generally used for making potentiometer wires due to its low temperature coefficient of resistance?

Which material is generally used for a potentiometer wire due to its low temperature coefficient of resistance?

Sensitivity of a potentiometer can be increased by:

What is the potential gradient of a potentiometer wire if a battery of $4V$ is connected across a $10m$ long wire of uniform resistance?

A potentiometer wire of length $10$ m has a resistance of $20 \Omega$. It is connected in series with a battery of $3$ V and a resistance of $10 \Omega$. The potential gradient of the wire is:

In a Wheatstone bridge, $P=2 \Omega$, $Q=2 \Omega$, $R=2 \Omega$, and $S=3 \Omega$. What resistance should be connected in parallel with $S$ to balance the bridge?

A $2V$ cell is connected across a potentiometer wire of $100 cm$ length. For a cell of EMF $1.5V$, the null point is $l$. If a resistance is added in series with the driver cell, the new null point $l'$ will:

A bridge circuit is constructed where the arms $AB, BC, CD$ and $DA$ have resistances $100 \Omega, 10 \Omega, 5 \Omega$ and $60 \Omega$ respectively. A galvanometer of $15 \Omega$ is connected between $B$ and $D$. If a potential difference of $10 \text{ V}$ is applied across $A$ and $C$, calculate the current flowing through the $10 \Omega$ resistor.

An engineer designs a sensing circuit using a Wheatstone bridge where $P=2 \Omega, Q=2 \Omega, R=2 \Omega$ and $S$ is a thermistor. At $0^{\circ}\text{C}$, $S=2 \Omega$. The bridge is balanced. The bridge is connected to a $6 \text{ V}$ battery. If the thermistor resistance drops to $1 \Omega$ at a certain temperature, calculate the current through a galvanometer of resistance $10 \Omega$ connected between the junctions of $P,Q$ and $R,S$.

In a precision Wheatstone bridge used for measuring the temperature coefficient of a metal wire, the four arms consist of resistors $P=10 \Omega$, $Q=100 \Omega$, $R=40 \Omega$, and an unknown resistance $S$. The bridge is balanced. If the bridge is powered by a $10 \text{ V}$ DC source with negligible internal resistance, and the galvanometer is replaced by a voltmeter of infinite resistance, what would the voltmeter read if $S$ increases by $10\%$ due to heating?