Compute the current in the wire if a charge of 120 C is flowing through a copper wire in 1 minute.

Why current is a scalar?

State microscopic form of Ohm’s law.

State macroscopic form of Ohm’s law.

Define electrical resistivity.

Define temperature coefficient of resistance.

Write a short note on superconductors?

What is electric power and electric energy?

Define current density.

If an electric field of magnitude 570 N C^–1, is applied in the copper wire, find the acceleration experienced by the electron.

A copper wire of cross-sectional area 0.5 mm² carries a current of 0.2 A. If the free electron density of copper is 8.4 x 10²⁸ m^-3 then compute the drift velocity of free electrons.

Determine the number of electrons flowing per second through a conductor, when a current of 32 A flows through it.

A potential difference across 24 Ω resistor is 12 V. What is the current through the resistor?

If the resistance of coil is 3 Ω at 20^oC and α = 0.004/^oC then determine its resistance at 100^oC.

Resistance of a material at 20^oC and 40^oC are 45 Ω and 85 Ω respectively. Find its temperature coefficient of resistivity.

A battery has an emf of 12 V and connected to a resistor of 3 Ω. The current in the circuit is 3.93 A. Calculate
(a) terminal voltage and the internal resistance of the battery
(b) power delivered by the battery and power delivered to the resistor

For the given circuit find the value of I.

In a meter bridge experiment with a standard resistance of 15 Ω in the right gap, the ratio of balancing length is 3:2. Find the value of the other resistance.

In a meter bridge experiment, the value of resistance in the resistance box connected in the right gap is 10 Ω. The balancing length is l₁ = 55 cm. Find the value of unknown resistance.

Find the heat energy produced in a resistance of 10 Ω when 5 A current flows through it for 5 minutes.

Derive the expression for power P=VI in electrical circuit.

State Kirchhoff ’s current rule.

State Kirchhoff ’s voltage rule.

State the principle of potentiometer.

What do you mean by internal resistance of a cell?

State Joule’s law of heating.

What is Seebeck effect?

What is Thomson effect?

What is Peltier effect?

The following graphs represent the current versus voltage and voltage versus current for the six conductors A, B, C, D, E, and F. Which conductor has least resistance and which has maximum resistance?

Lightning is very good example of natural current. In typical lightning, there is 10⁹ J energy transfer across the potential difference of 5 x 10⁷ V during a time interval of 0.2 s.

Using this information, estimate the following quantities.
(a) total amount of charge transferred between cloud and ground
(b) the current in the lightning bolt
(c) the power delivered in 0.2 s.

A copper wire of 10^-6 m² area of cross section, carries a current of 2 A. If the number of free electrons per cubic meter in the wire is 8\(\times\)10²⁸, Calculate the current density and average drift velocity of electrons.

The resistance of a nichrome wire at 20^oC is 10 Ω. If its temperature coefficient of resistanc is 0.004^oC, find its resistance of the wire at boiling point of water. Comment on the result.

The rod given in the figure is made up of two different materials.

Both have square cross sections of 3 mm side. The resistivity of the first material is 4 x 10^-3 Ωm and that of second material has resistivity of 5 x 10^-3 Ωm. What is the resistance of rod between its ends?

An electronics hobbyist is building a radio which requires 150 Ω in her circuit. But she has only 220 Ω, 79 Ω and 92 Ω resistors available. How can she connect the available resistors to get desired value of resistance?

A cell supplies a current of 0.9 A through a 2 Ω resistor and a current of 0.3 A through a 7 Ω resistor. Calculate the internal resistance of the cell.

Calculate the currents in the following circuit.

A potentiometer wire has a length of 4 m and resistance of 20 Ω. It is connected in series with resistance of 2980 Ω and a cell of emf 4 V. Calculate the potential gradient along the wire.

Determine the current flowing through the galvanometer (G) as shown in the figure.

Two cells each of 5V are connected in series with a 8 Ω resistor and three parallel resistors of 4 Ω, 6 Ω, and 12 Ω. Draw a circuit diagram for the above arrangement. Calculate
(i) the current drawn from the cells
(ii) current through each resistor

Four bulbs P, Q, R, S are connected in a circuit of unknown arrangement. When each bulb is removed one at a time and replaced, the following behavior is observed.

	P	Q	R	S
P removed	*	on	on	on
Q removed	on	*	on	off
R removed	off	off	*	off
S removed	on	off	on	*

Draw the circuit diagram for these bulbs.

In a potentiometer arrangement, a cell of emf 1.25 V gives a balance point at 35 cm length of the wire. If the cell is replaced by another cell and the balance point shifts to 63 cm, what is the emf of the second cell?