NCERT Exemplar solutions for Science [English] Class 10 chapter 12 - Electricity [Latest edition]

A cell, a resistor, a key and ammeter are arranged as shown in the circuit diagrams of Figure. The current recorded in the ammeter will be

(i)	(ii)	(iii)

In the following circuits (Figure), heat produced in the resistor or combination of resistors connected to a 12 V battery will be

(i)	(ii)	(iii)

Electrical resistivity of a given metallic wire depends upon

A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly

Identify the circuit in which the electrical components have been properly connected.

(i)	(ii)	(iii)	(iv)

What is the maximum resistance which can be made using five resistors each of 1/5 Ω?

What is the minimum resistance which can be made using five resistors each of 1/5 Ω?

The proper representation of series combination of cells obtaining maximum potential is

(i)	(ii)	(iii)	(iv)

Which of the following represents voltage?

A cylindrical conductor of length l and uniform area of cross section A has resistance R. Another conductor of length 2l and resistance R of the same material has area of cross section 

A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances R₁, R₂ and R₃ respectively. Which of the following is true? 

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be 

The resistivity does not change if

In an electrical circuit three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness?

In an electrical circuit two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be

An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?

Two resistors of resistance 2 Ω and 4 Ω when connected to a battery will have

Unit of electric power may also be expressed as

A child has drawn the electric circuit to study Ohm’s law as shown in Figure. His teacher told that the circuit diagram needs correction. Study the circuit diagram and redraw it after making all corrections.

Three 2 Ω resistors, A, B and C, are connected as shown in Figure. Each of them dissipates energy and can withstand a maximum power of 18 W without melting. Find the maximum current that can flow through the three resistors?

A current of 1 ampere flows in a series circuit containing an electric lamp and a conductor of 5 Ω when connected to a 10 V battery. Calculate the resistance of the electric lamp.

Now if a resistance of 10 Ω is connected in parallel with this series combination, what change (if any) in current flowing through 5 Ω conductor and potential difference across the lamp will take place? Give reason.

B₁, B₂ and B₃ are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.

1.  What happens to the glow of the other two bulbs when the bulb B₁ gets fused?
2. What happens to the reading of A₁, A₂, A₃ and A when the bulb B₂ gets fused?
3. How much power is dissipated in the circuit when all the three bulbs glow together?

Three incandescent bulbs of 100 W each are connected in series in an electric circuit. In another circuit another set of three bulbs of the same wattage are connected in parallel to the same source.

1. Will the bulb in the two circuits glow with the same brightness? Justify your answer.
2. Now let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit? Give reason.

What is electrical resistivity of a material? What is its unit? Describe an experiment to study the factors on which the resistance of conducting wire depends.

How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?

Find out the following in the electric circuit given in Figure

1. Effective resistance of two 8 Ω resistors in the combination
2. Current flowing through 4 Ω resistor
3. Potential difference across 4 Ω resistance
4. Power dissipated in 4 Ω resistor
5. Difference in ammeter readings, if any.