# MCQs For NCERT Class 10 Science Chapter 13 Magnetic Effect of Electric Current

Please refer to the MCQ Questions for Class 10 Science Chapter 13 Magnetic Effect of Electric Current with Answers. The following Magnetic Effect of Electric Current Class 10 Science MCQ Questions have been designed based on the current academic year syllabus and examination guidelines for Class 10. Our faculty has designed MCQ Questions for Class 10 Science with Answers for all chapters as per your NCERT Class 10 Science book.

## Magnetic Effect of Electric Current Class 10 MCQ Questions with Answers

Please see below Magnetic Effect of Electric Current Class 10 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. Circuit Breaker Device which can be used in place of fuse in domestic electric wiring is called :
(a) CBD
(b) DCB
(c) MCD
(d) MCB

D

Question. The frequency of alternating current (a.c.) supply in India is :
(a) 0 Hz
(b) 50 Hz
(c) 60 Hz
(d) 100 Hz

B

Question. Which of the following property of a proton can change while it moves freely in a magnetic field?
(a) Mass
(b) Speed
(c) Velocity
(d) Charge

C

Question. Which of the following correctly describes the magnetic field near a long straight wire ?
(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.

D

Question. A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is :
(a) towards south
(b) towards east
(c) downward
(d) upward

D

Question. A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each :
(a) two revolutions
(b) one revolution
(c) half revolution
(d) one-fourth revolution

C

Question. The essential difference between an A.C. generator and a D.C. generator is that :
(a) A.C. generator has an electromagnet while a D.C. generator has permanent magnet.
(b) D.C. generator will generate a higher voltage.
(c) A.C. generator will generate a higher voltage.
(d) A.C. generator has slip rings while the D.C. generator has a commutator.

D

Question. The direction of force acting on a current carrying conductor placed in a magnetic field can be obtained by :
(a) Fleming’s left hand rule.
(b) Fleming’s right hand rule.
(c) Clock face rule.
(d) Ampere’s swimming rule.

A

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

C

Question. The magnetic field inside a long straight solenoid carrying current :
(a) is zero.
(b) decreases as we move towards its end.
(c) increases as we move towards its end.
(d) is the same at all points.

D

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

A

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

C

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

C

Question. An MCB which cuts off the electricity supply in case of short-circuiting or overloading works on the :
(a) chemical effect of current
(b) heating effect of current
(c) magnetic effect of current
(d) electroplating effect of current

C

Question. The essential difference between an AC generator and a DC generator is that :
(a) AC generator has an electromagnet while a DC generator has permanent magnet.
(b) DC generator will generate a higher voltage.
(c) AC generator will generate a higher voltage.
(d) AC generator has slip rings while the DC generator has a commutator.

D

Question. Each one of the following changes will increase emf (or voltage) in a simple generator except :
(a) increasing the number of turns in the armature coil
(b) winding the coil on a soft iron armature
(c) increasing the size of the gap in which the armature turns
(d) increasing the speed of rotation

C

Question. The maximum number of 40 W tube-lights connected in parallel which can safely be run from a 240 V supply with a 5 A fuse is :
(a) 5
(b) 15
(c) 20
(d) 30

D

Question. In normal use, a current of 3.5 A flows through a hair dryer. Choose a suitable fuse from the following :
(a) 3 A
(b) 5 A
(c) 10 A
(d) 30 A

D

Question. An induced current is produced when a magnet is moved into a coil. The magnitude of induced current does not depend on :
(a) the speed with which the magnet is moved
(b) the number of turns of the coil
(c) the resistivity of the wire of the coil
(d) the strength of the magnet

C

Question. The frequency of direct current (d.c.) is :
(a) 0 Hz
(b) 50 Hz
(c) 60 Hz
(d) 100 Hz

A

Question: A plotting compass is placed near the south pole of a bar magnet. The pointer of plotting compass will:
(a) point away from the south pole
(b) point parallel to the south pole
(c) point towards the south pole
(d) point at right angles to the south pole

C

Question: Which of the following statements is incorrect regarding magnetic field lines?
(a) The direction of magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points.
(b) Magnetic field lines are closed curves
(c) If magnetic field lines are parallel and equidistant,they represent zero field strength
(d) Relative strength of magnetic field is shown by the degree of closeness of the field lines

C

Question: A magnet attracts:
(a) plastics
(b) carbon
(c) aluminium
(d) iron and steel

D

Question: The front face of a circular wire carrying current behaves like a north pole, The direction of current in this face of the circular wire is:
(a) clockwise
(b) downwards
(c) anticlockwise
(d) upwards

C

Question:The magnetic field lines in the middle of the current carrying solenoid are
(a) circles
(b) spirals
(c) parallel to the axis of the tube
(d) perpendicular to the axis of the tube

C

Question: The most suitable material for making the core of an electromagnet is:
(a) soft iron
(b) brass
(c) aluminium
(d) steel

A

Question: An electron beam enter   s a magnetic field at right angles to it as shown in the Figure. Magnetic field Electron beam The direction of force acting on the electron beam will be: 8
(a) to the left
(b) to the right
(c) into the page
(d) out of the page

C

Question: The force experienced by a current-carrying conductor placed in a magnetic field is the largest when the angle between the conductor and the magnetic field is:
(a) 45o
(b) 60o
(c) 90o
(d)180o

C

Question: 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

C

Question: The force exerted on a current-carrying wire placed in a magnetic field is zero when the angle between the wire and the direction of magnetic field is:
(a) 45o
(b) 60o
(c) 90o
(d) 180o

D

Question: A small magnet is placed perpendicular to a uniform magnet field. The forces acting on the magnet will result in
(a) Rotational motion
(b) Translatory motion
(c) No motion at all
(d) Translational and rotational motion both

A

Question: A circular loop placed in a plane perpendicular to the plane of paper carries a current when the key is ON The current as seen from points A and B (in the plane of paper and on the axis of the coil) is anti clockwise and clockwise respectively. The magnetic field lines point from B to A. The N-pole of the resultant magnet is on the face close to
(a) A
(b) B
(c) A if the current is small, and B if the current is large
(d) B if the current is small and A if the current is large

A

Question: By removing the inducing magnet, the induced magnetism is
(a) Finished after some time
(b) Finished just after
(c) Not finished for a long time
(d) Not changed

B

Question. If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be :
(a) west pole
(b) south pole
(c) north pole
(d) east pole

A

Question. The most suitable material for making the core of an electromagnet is :
(a) soft iron
(b) brass
(c) aluminium
(d) steel

A

Question. A plotting compass is placed near the south pole of a bar magnet. The pointer of plotting compass will :
(a) point away from the south pole
(b) point parallel to the south pole
(c) point towards the south pole
(d) point at right angles to the south pole

C

Question. The metallic pointer of a plotting compass gets deflected only when it is placed near a bar magnet because the pointer has :
(a) electromagnetism
(b) permanent magnetism
(c) induced magnetism
(d) ferromagnetism

B

Question. Which of the following statements is incorrect regarding magnetic field lines ?
(a) The direction of magnetic field at a point is taken to be the direction in which the north pole of a magnetic compass needle points.
(b) Magnetic field lines are closed curves
(c) If magnetic field lines are parallel and equidistant, they represent zero field strength
(d) Relative strength of magnetic field is shown by the degree of closeness of the field lines

C

Question. In household circuits, is a fuse wire connected in series or in parallel ?

In series

Question. How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building ?

In parallel

Question. What is the major difference between the simple alternator and most practical alternators ?

Simple alternator : Magnet fixed and coil rotates ; Practical alternator : Coil fixed and magnet rotates

Question. Why are Thermal Power Stations usually located near a river ?

To obtain water for making steam for turning turbines and for cooling spent steam to condense it back into hot water for making fresh steam

Question. List three sources of magnetic fields.

Permanent magnets ; Electromagnets ;

Question. A motor converts one form of energy into another. Name the two forms.

Electrical energy to Mechanical energy

Question. In an electric motor, which of the following remains fixed and which rotates with the coil ? Commutator ; Brush

Remains fixed : Brush ; Rotates with the coil : Commutator

Question. Which effect of current can be utilised in detecting a currentcarrying wire concealed in a wall ?

Magnetic effect

Question. State qualitatively the effect of inserting an iron core into a current-carrying solenoid.

Magnetic field becomes very strong

Question. When is the force experienced by a current-carrying conductor placed in a magnetic field largest ?

When the current-carrying conductor is at right angles to the magnetic field

Question. Name the device which converts mechanical energy into electric energy.

Electric generator

Fill in the following blanks with suitable words :

Question. The lines of…………..round a straight current-carrying conductor are in the shape of………….

magnetic field ; concentric circles

Question. The magnetic effect of a coil can be increased by increasing the number of………….., increasing the …………., or inserting an…………..core.

turns ; current ; iron

Question. Fleming’s Rule for the motor effect uses the ……………  hand.

Left

Question. A fuse should always be placed in the ……………. wire of a main circuit.

Live

Question. An electric motor is a device which transform …………. energy to ………… energy.

Electrical, mechanical.

Question. Fleming’s Rule for the motor effect uses the…………… hand.

left

Question. The earth’s magnetic field is rather like that of a ……… magnet with its……..pole in the northern

hemisphere       bar ; south

Question. A motor contains a kind of switch called a ………… which reverses the current every half…………

commutator; rotation;

Assertion and Reasoning Based Questions

Directions : In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as :
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true, but reason is not the correct explanation of assertion.
(c) If assertion is true, but reason is false.
(d) If assertion is false but reason is true.

Question. Assertion : Electric generator uses mechanical energy and converts it into electrical energy.
Reason : Electric generator works on the principle of Electromagnetic induction.

A

Question. Assertion : A pump operated by electric motor starts pumping liquid.
Reason : Motor converts mechanical energy to electrical energy.

C

Question. Assertion : Frequency of AC circuits is 50 Hz in India.
Reason : DC is alternating in nature.

C

Question. Assertion : Galvanometer is used to measure polarity.
Reason : Galvanometer is an instrument which is used to detect current in any circuit.

B

Question. Assertion : A fault occurred in the domestic lines, but all the equipment’s are safe.
Reason : Potential difference is only 220 V in our country in domestic lines.

B

Creating Based Questions

Question. Blair wants to measure magnetic field. Suggest her a better instrument which would measure magnetic field approximately.
Answer : Blair can use flux meter to measure the magnetic field since it can be used to predict the flux amount produced in the permanent magnet due to its low controlling torque and its heavy electromagnetic damping. It is better than a ballistic galvanometer since it has high torque and its accuracy is less.

Question. For experimenting purpose, Ram made two electromagnets by wrapping a few turns of wire on one nail and doubled the number of turns of wire for the other nail and let the same amount of electric current passed through it. From his inference, which one tends to have larger magnetic strength ?
Answer : The number of turns of the wire wrapped over the two iron nails is in the ratio of 2 : 1. Electromagnetic strength has a direct relationship with the number of turns wrapped over it. The strength of electromagnet increases with increase in a number of turns of the wire wrapped over the nail and the current passing through them. Hence, the one with more number of turns tends to have more magnetic strength.

Question. Using the following information form a pathway to determine the direction of the electric current in electric generator. And also include information that is not mentioned below to complete it. Induced electric current, Orthogonal, Magnetic field, Index finger, Middle finger, Thumb, Right – hand.
Answer : We can find the direction of the electric current in the electric generator using Fleming’s right- and rule. This rule is a mnemonics with which we can easily determine the direction of the electric current.
In right hand, → Three fingers → Index finger → Middle finger → Thumb → Placed orthogonal position → Thumb defines the direction of the motion of the conductor → Index finger defines the direction of the magnetic field → Middle finger defines the direction of the induced current → Used to find the direction of current in electric generator → Also known as generator rule.

Question. Selena measures the magnetic field produced by an infinitely long wire, a rectangular loop, a solenoid of finite length, a circular loop where all the four carries the same amount of current. After her experiment, she tends to notice that the magnetic field produced by certain cases is similar to the magnetic field produced by the bar magnet. Find out the cases in which both the magnetic fields are equal ?
Answer : Solenoid is the only thing which is tightly-packed in terms of close loops. If current is passed inside a solenoid which is of finite length, the closely packed loops inside it produce a magnetic field which resembles the magnetic field of a bar magnet. Other than this, the circular or rectangular loop doesn’t produce much magnetic field as that of a bar magnet.

Question. Using the following information form a pathway that defines the working of the electric motor. And also include information that is not mentioned below to complete it. Battery, Horse-shoe magnet, vertical position, Commutator, rectangle coil, Magnetic force, horizontal position.
Answer : Rectangle coil is placed between horse-shoe magnet → Coil is connected to the battery through brush and commutator → The current flow through the coil which is placed between magnetic field → Rectangle coil rotates from the horizontal position → The current stop flowing when the coil attains vertical position because the brush and the commutator ring will not in connection → Though the coil keeps rotates because of the momentum from the earlier rotation → now the coil attains horizontal position → Coil again starts to rotate → With the help of Fleming’s left-hand rule,the direction of the rotation of the coil is determined.

Read the following and answer any four questions from 18 (i) to 18 (v):
In a certain water fountain, a pump takes water from a large pool and pumps it up through the water flows along the trough and falls through a hole in the bottom. As the water falls, it turns a water wheel and returns to the pool. Assume the water fountain is analogous to an electric circuit

Question. What would be analogous to the pool?
(a) A resistor
(b) An inductor
(c) A ground
(d) A wire

C

Question. What would be analogous to electric potential?
(a) Water
(b) Flow velocity
(c) Volume flow rate
(d) Height of water

D

Question. What would be analogous to electric current?
(a) Water
(b) Flow velocity
(c) Volume flow rate
(d) Height of water

C

Question. What is relation between electric potential and electric current.
(a) V = I/R
(b) R = VI
(c) R/I = V
(d) V = IR

D

Question. What would be analogous to the water pump?
(a) A motor
(b) A resistor
(c) A battery
(d) A light bulb

C

3. A DC generator also called a dynamo converts Mechanical energy into electrical energy (dc). It works on the principle that when a coil rotates in a uniform magnetic field, a current is indued current is determined by Fleming’s right hand rule. The schematic diagram of a dc generator is as shown in figure.

(a) The essential difference between an ac generator and a dc generator is that :
(i) ac generator has an electromagnet while a dc generator has permanent magnet.
(ii) dc generator will generate a higher voltage.
(iii) ac generator will generate a higher voltage.
(iv) ac generator has slip rings while the dc generator has a commutator.
(b) What is the frequency of dc ?
(c) What type of dyanamo is used in a bicycle ?
(d) A DC motor is rotating in clockwise direction. How can the direction of rotation be reversed ?