A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.

In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.

Which of the following has negative temperature coefficient of resistance?

The temperature co-efficient of resistance for alloys is _____________.

Define current density.

Write down the various forms of expression for power in electrical circuit.

Distinguish between ohmic & non-ohmic device.

The resistivity of materials depends upon what parameters?

What is electric fuse?

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

Two resistors when connected in series and parallel, their equivalent resistances are 15 Ω and \(\frac{56}{15}\)Ω respectively. Find the individual resistances.

Derive an expression of drift velocity and write the relation between drift velocity and mobility.

In a circuit containing internal resistance r. Find the power delivered.

Explain Peltier effect.

Two electric bulbs marked 20 W – 220 V and 100 W – 220 V are connected in series to 440 V supply. Which bulb will get fused?

For the given circuit find the value of I.

Two students A & B were asked to pick a resistor of 25 k from a collection of carbon resistors. A picked a resistors with bands of colours of red, green, orange, white. B picked a resistor with bands of colours: black, green, red who picked the correct resistor?

A conductor of length I is connected to d.c. source of potential V. If the length of the conductor is doubled by treating it, keeping V constant, explain how do the following factors vary in the conductor
(i) Drift velocity.
(ii) Resistor
(iii) Resistivity.