Class 10 Science

Chapter 11 Solutions — Electricity

Open Solutions PDF →Also seeTextbook page→

Open Solutions PDFReads in your browser→Also seeTextbook page→

Solutions

Overview

Step-by-step NCERT solutions for Electricity (Chapter 11, CBSE Class 10 Science) — the full working for every question, not just the final answer. You can also read the Electricity textbook chapter.

Solved

What these solutions cover

All 40 questions in Electricity are solved in the PDF. Here's what's inside, exercise by exercise:

Electric Current and Circuit

What does an electric circuit mean?
Define the unit of current.
Calculate the number of electrons constituting one coulomb of charge.

Electric Potential and Potential Difference

Name a device that helps to maintain a potential difference across a conductor.
What is meant by saying that the potential difference between two points is 1 V?
How much energy is given to each coulomb of charge passing through a 6 V battery?

Ohm's Law and Resistance

On what factors does the resistance of a conductor depend?
Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?
Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?

Series and Parallel Circuits

How is a voltmeter connected in the circuit to measure the potential difference between two points?
A copper wire has diameter 0.5 mm and resistivity of 1.6 x 10^(-8) ohm m. What will be the length of this wire to make its resistance 10 ohm? How much does the resistance change if the diameter is doubled?
The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below: I (amperes): 0.5, 1.0, 2.0, 3.0, 4.0 V (volts): 1.6, 3.4, 6.7, 10.2, 13.2 Plot a graph between V and I and calculate the resistance of that resistor.

Heating Effect of Electric Current and Electric Power

When a 12 V battery is connected to an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
A battery of 9 V is connected in series with resistors of 0.2 ohm, 0.3 ohm, 0.4 ohm, 0.5 ohm and 12 ohm, respectively. How much current would flow through the 12 ohm resistor?
How many 176 ohm resistors (in parallel) are required to carry 5 A on a 220 V line?
4.
Show how you would connect three resistors, each of resistance 6 ohm, so that the combination has a resistance of
- (i) 9 ohm,
- (ii) 4 ohm.
5.
What is
- (a) the highest,
- (b) the lowest total resistance that can be secured by combinations of four coils of resistance 4 ohm, 8 ohm, 12 ohm, 24 ohm?

Heating Effect of Electric Current

Why does the cord of an electric heater not glow while the heating element does?
Compute the heat generated while transferring 96000 coulombs of charge in one hour through a potential difference of 50 V.
An electric iron of resistance 20 ohm takes a current of 5 A. Calculate the heat developed in 30 s.

Electric Power

What determines the rate at which energy is delivered by a current?
An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.

Electricity — Comprehensive Exercise

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R', then the ratio R/R' is:
2.
Which of the following terms does not represent electrical power in a circuit?
- (a) I²R
- (b) IR²
- (c) VI
- (d) V²/R
An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be:
Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then connected in parallel in a circuit across the same potential difference. Find the ratio of heat produced in series and parallel combinations.
How is a voltmeter connected in the circuit to measure the potential difference between two points?
A copper wire has diameter 0.5 mm and resistivity of 1.6 x 10^(-8) ohm m. What will be the length of this wire to make its resistance 10 ohm? How much does the resistance change if the diameter is doubled?
The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below: I (amperes): 0.5, 1.0, 2.0, 3.0, 4.0 V (volts): 1.6, 3.4, 6.7, 10.2, 13.2 Plot a graph between V and I and calculate the resistance of that resistor.
When a 12 V battery is connected to an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
A battery of 9 V is connected in series with resistors of 0.2 ohm, 0.3 ohm, 0.4 ohm, 0.5 ohm and 12 ohm, respectively. How much current would flow through the 12 ohm resistor?
How many 176 ohm resistors (in parallel) are required to carry 5 A on a 220 V line?
11.
Show how you would connect three resistors, each of resistance 6 ohm, so that the combination has a resistance of
- (i) 9 ohm,
- (ii) 4 ohm.
12.
What is
- (a) the highest,
- (b) the lowest total resistance that can be secured by combinations of four coils of resistance 4 ohm, 8 ohm, 12 ohm, 24 ohm?
Why does the cord of an electric heater not glow while the heating element does?
Compute the heat generated while transferring 96000 coulombs of charge in one hour through a potential difference of 50 V.
An electric iron of resistance 20 ohm takes a current of 5 A. Calculate the heat developed in 30 s.
What determines the rate at which energy is delivered by a current?
An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.

Keep solving