# Class 10 Science: Case Study Chapter 13 Magnetic Effects of Electric Current PDF Download

In CBSE Class 10 Science Paper, Students will have to answer some questions based on Assertion and Reason. There will be a few questions based on case studies and passage-based as well. In that, a paragraph will be given.

Here we are providing you with Class 10 Science Chapter 13 Magnetic Effects of Electric Current Case Study Questions, by practicing these Case Study and Passage Based Questions will help you in your Class 10th Board Exam.

# Case Study Chapter 12 Magnetic Effects of Electric Current

Here, we have provided case-based/passage-based questions for Class 10 Science Chapter 13 Magnetic Effects of Electric Current

Case Study/Passage Based Questions

Question 1:

An electric motor is a rotating device that converts electrical energy into mechanical energy electric motors are used as an important component in electric fans, refrigerators, mixer, washing machines, computers, MP3 players etc. Motor Works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it, a force acts on the coil which rotates it continuously. When the coil rotates the shaft attached to it also rotates. In this way the electrical energy supplied to the motor is converted into the mechanical energy of rotation.

1.1) When the current is switched on, an electric fan converts :
(a) electrical energy into mechanical energy
(b) chemical energy into mechanical energy
(c) electrical energy into mechanical energy
(d) mechanical energy into electrical energy

Answer: (c) electrical energy into mechanical energy

1.2) In an electric motor, the direction of current in the coil changes once in each
(a) two rotations
(b) one rotation
(c) half rotation
(d) one-fourth rotation

1.3) An electron beam enters a magnetic field at right angles to it. The direction of force acting on the electron beam will be :
(a) to the right
(b) to the left
(c) into the page
(d) out of the page

1.4) A magnetic field exerts no force on :
(a) an unmagnetised iron bar
(b) a stationary electric charge
(c) a magnet
(d) an electric charge moving perpendicular to its direction

Answer: (b) a stationary electric charge

1.5) Which of the following has no effect on the size of the turning effect on the coil of an electric motor?
(a) The amount of the current in the coil.
(b) The number of turns in the coil.
(c) The direction of the current in the coil.
(d) The strength of the magnetic field.

Answer: (c) The direction of the current in the coil

Question 2:

An insulated copper wire wound on a cylindrical cardboard tube such that its length is greater than its diameter is called a solenoid. When an electric current is passed through the solenoid, it produces a magnetic field around it. The magnetic field produced by a current-carrying solenoid is similar to the magnetic field produced by a bar magnet. The field lines inside the solenoid are in the form of parallel straight lines. The strong magnetic field produced inside a current-carrying solenoid can be used to magnetize a piece of a magnetic material like soft iron when placed inside the solenoid. The strength of the magnetic field produced by a current-carrying solenoid is directly proportional to the number of turns and strength of the current in the solenoid.

(i) The strength of magnetic field inside a long current-carrying straight solenoid is
(a) more at the ends than at the centre
(b) minimum in the middle
(c) same at all points
(d) found to increase from one end to the other.

Answer: (c) same at all points

(ii) The north-south polarities of an electromagnet can be found easily by using

Answer: (c) Clock face rule ​

(iii) For a current in a long straight solenoid N-and S-poles are created at the two ends. Among the following statements, the incorrect statement is
(a) The field lines inside the solenoid are in the form of straight lines which indicates that the magnetic field is the same at all points inside the solenoid.
(b) The strong magnetic field produced inside the solenoid can be used to magnetise a piece of magnetic material like soft iron, when placed inside the coil.
(c) The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet.
(d) The N- and S-poles exchange position when the direction of current through the solenoid is reversed.

Answer: (c) The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet. ​

(iv) A long solenoid carrying a current produces a magnetic field B along its axis. If the current is double and the number of turns per cm is halved, then new value of magnetic field is