CBSE Class 10 Science Chapter 13: Magnetic Effects of Electric Current NCERT Solutions

Reviewed by NCERT Help Editorial Team · Updated on 29 Jul 2026

NCERT Solutions PDF Class 10 PDF

This chapter delves into the fascinating world of magnetic effects produced by electric currents. Students will explore the nature of magnetic fields around current-carrying wires, understand the principle of electromagnetic induction, and learn about devices like generators. The solutions cover key concepts such as the right-hand thumb rule, the phenomenon of induced current, and the difference between AC and DC generators. It also addresses the critical scenario of short circuits and their impact on current. These NCERT Solutions provide clear explanations and step-by-step answers to help students grasp the fundamental principles and prepare effectively for their examinations.

Home

Quick info

Board	CBSE
Class	Class 10
Subject	Science
Session	2026
Language	English
Type	NCERT Solutions
Chapter	Chapter 13: Magnetic Effect of Electric Current

Chapter summary

Chapter 13 of the CBSE Class 10 Science syllabus focuses on the Magnetic Effects of Electric Current. The NCERT Solutions for this chapter explain the magnetic field patterns around a straight current-carrying wire, the phenomenon of electromagnetic induction, and the working principles of generators. It clarifies the distinction between AC and DC generators and discusses the consequences of short circuits. These solutions are designed to reinforce understanding of these core concepts through clear explanations and problem-solving.

Learning outcomes

Understand the magnetic field pattern around a long straight current-carrying wire.
Define and explain the phenomenon of electromagnetic induction.
Identify the device used for producing electric current.
Differentiate between AC and DC generators based on their components.
Explain the effect of a short circuit on the current in an electrical circuit.

Topics covered

Paper topics

Magnetic Field due to Current
Right-Hand Thumb Rule
Electromagnetic Induction
Induced Current
Electric Generator
AC Generator
DC Generator
Slip Rings
Commutator
Short Circuit

Important topics

Magnetic Field due to Current
Electromagnetic Induction
AC Generator vs DC Generator
Short Circuit Effects

PDF preview

Read page by page below. PDF is streamed from the official NCERT website — no download button on this page.

Loading document …

Page of

Loading page …

Questions and Solutions

Exercises

Question 1

Which of the following correctly describes the magnetic field near a long straight wire carrying electric current? (a) The field consists of straight lines perpendicular to the wire. (b) The field consists of straight lines parallel to the wire. (c) The field consists of radial lines originating from the wire. (d) The field consists of concentric circles centred on the wire.

Solution: The correct option is (d). When an electric current flows through a long straight wire, it generates a magnetic field around it. According to the right-hand thumb rule, if you point your thumb in the direction of the current, your fingers curl around the wire in the direction of the magnetic field lines. These field lines are observed to be in the form of concentric circles, with the wire at the center. Therefore, the magnetic field near a long straight wire consists of concentric circles centered on the wire.

Question 2

The phenomenon of electromagnetic induction is described as: (a) the process of charging a body. (b) the process of generating a magnetic field due to a current passing through a coil. (c) producing an induced current in a coil due to relative motion between a magnet and the coil. (d) the process of rotating a coil in an electric motor.

Solution: The correct option is (c). Electromagnetic induction is the process by which a changing magnetic field in the vicinity of a conductor induces an electromotive force (and hence a current, if the circuit is closed) in that conductor. This change in magnetic field is typically achieved by relative motion between a magnet and a coil, or by changing the current in a nearby coil. Options (a), (b), and (d) describe different physical phenomena: (a) is electrostatic charging, (b) is the magnetic effect of current, and (d) relates to electric motors.

Question 3

The device used for producing electric current is called a: (a) generator. (b) galvanometer. (c) ammeter. (d) motor.

Solution: The correct option is (a). A generator is an electrical device that converts mechanical energy into electrical energy. It operates on the principle of electromagnetic induction, where relative motion between a conductor and a magnetic field induces an electric current. A galvanometer detects and measures small currents, an ammeter measures larger currents, and a motor converts electrical energy into mechanical energy.

Question 4

What is the essential difference between an AC generator and a DC generator? (a) An AC generator has an electromagnet while a DC generator has a permanent magnet. (b) A DC generator will generate a higher voltage. (c) An AC generator will generate a higher voltage. (d) An AC generator has slip rings while the DC generator has a commutator.

Solution: The correct option is (d). The fundamental difference between AC and DC generators lies in the mechanism used to connect the rotating coil to the external circuit. An AC generator uses slip rings, which allow the current to be collected as alternating current. A DC generator uses a commutator, which acts as a split ring, reversing the connections every half rotation to ensure that the current flows in only one direction in the external circuit, producing direct current. Options (a), (b), and (c) are not universally true distinctions.

Question 5

At the time of a short circuit, the current in the circuit: (a) reduces substantially. (b) does not change. (c) increases heavily. (d) varies continuously.

Solution: The correct option is (c). A short circuit occurs when the live wire and the neutral wire (or earth wire) come into direct contact, bypassing the normal load resistance. This creates a path of very low resistance. According to Ohm's law (

V = IR

), if the resistance (R) becomes extremely small, the current (I) flowing through the circuit will increase very heavily, potentially causing damage or fire.

Common mistakes

Confusing the direction of magnetic field lines with the direction of current.
Misunderstanding the conditions required for electromagnetic induction.
Incorrectly identifying the function of generators versus motors or galvanometers.
Not fully grasping the drastic increase in current during a short circuit.

Revision tips

Review the right-hand thumb rule to visualize magnetic field directions.
Focus on the definition and conditions for electromagnetic induction.
Understand the key difference between AC and DC generators (slip rings vs. commutator).
Memorize the behavior of current during a short circuit.

Practice MCQs

Q1. What is the shape of the magnetic field lines around a long straight wire carrying current?

Q2. Electromagnetic induction is the process of:

Q3. Which device is primarily used for producing electric current?

Q4. What is the main distinguishing feature between an AC generator and a DC generator?

Q5. What happens to the current in a circuit during a short circuit?

Frequently asked questions

What is the magnetic field like near a long straight wire carrying current?

The magnetic field near a long straight wire carrying current consists of concentric circles centered on the wire. The direction of these circles can be determined using the right-hand thumb rule.

What is electromagnetic induction?

Electromagnetic induction is the phenomenon where an electric current is produced in a coil due to a change in the magnetic field around it, typically caused by the relative motion between the coil and a magnet.

What is the main function of a generator?

A generator is a device used to produce electric current by converting mechanical energy into electrical energy, often utilizing the principle of electromagnetic induction.

What is the key difference between an AC generator and a DC generator?

The primary difference is the mechanism used to collect the current: AC generators use slip rings, while DC generators use a commutator, which results in different types of current output.

What happens to the current during a short circuit?

During a short circuit, the resistance in the circuit drops drastically, causing the current to increase very heavily, which can be dangerous.

How do these NCERT solutions help in exam preparation?

These solutions provide clear, step-by-step explanations for each question, helping students understand the underlying concepts and methods required to solve problems related to magnetic effects of electric current for their exams.

Content reviewed by the NCERT Help team. Editorial Team and update policy

NCERT Solutions PDF PDF on NCERT Help. URL unchanged for search indexing.