Class 10 Science Chapter 12 MCQ Magnetic Effects of Electric Current
MCQ on Magnetic Effects of Electric Current Class 10
Question 1.
Magnetic effect of current was discovered by
A) Oersted
B) Faraday
C) Bohr
D) Ampere
Answer:
A) Oersted
Question 2.
Inside the magnet, the field lines moves
A) from North to South
B) from South to North
C) away from South pole
D) away from North pole
Answer:
B) from South to North
Question 3.
Relative strength of magnetic field at a point in the space surrounding the magnet is shown by the
A) length of magnet
B) thickness of magnet
C) degree of closeness of the field
D) resistance offered by the surroundings
Answer:
C) degree of closeness of the field
Question 4.
Which of the following statement is not correct about the magnetic field ?
A) Magnetic field lines from a continuous closed curve
B) Magnetic field line do not intersect each other
C) Direction of tangent drawn at any point on the magnetic field line curve gives the direction of magnetic field at that point.
D) Outside the magnet, magnetic field lines go from South to North pole of the magnet.
Answer:
D) Outside the magnet, magnetic field lines go from South to North pole of the magnet.
Question 5.
By which instrument, the presence of magnetic field be determined?
A) Magnetic Needle
B) Ammeter
C) Galvanometer
D) Voltmeter
Answer:
A) Magnetic Needle
Question 6.
The pattern of the magnetic field produced by the straight current carrying conducting wire is
A) in the direction opposite to the current
B) in the direction parallel to the wire
C) circular around the wire
D) in the same direction of current
Answer:
C) circular around the wire
Question 7.
The nature of magnetic field line passing through the centre of current carrying circular loop is ………………….
A) Circular
B) Ellipse
C) Parabolic
D) Straight line
Answer:
D) Straight line
Question 8.
Polarity of a current carrying solenoid can be determined by
A) Use of compass needle
B) Right hand thumb rule
C) Fleming left hand rule
D) Either (A) or (B)
Answer:
D) Either (A) or (B)
Question 9.
The factors on which one magnetic field strength produced by current carrying solenoids depends are
A) Magnitude of current
B) Number of turns
C) Nature of core material
D) All of the above
Answer:
Question 10.
A soft iron bar is introduced inside the current carrying solenoid, the magnetic field inside the solenoid
A) will decrease
B) will remains the same
C) will increase
D) will become zero
Answer:
C) will increase
Question 11.
Which of the following factors affect the strength of force experience by a current carrying conduct in a uniform magnetic field ?
A) Magnetic field strength
B) Magnitude of current in a conductor
C) Length of the conductor within magnetic field
D) All of the above
Answer:
D) All of the above
Question 12.
Earth wire carries
A) current
B) voltage
C) no current
D) heat
Answer:
C) no current
Question 13.
Overloading is due to
A) insulation of wire is damaged
B) fault in the appliances
C) accidental hike in supply voltage
D) all of the above
Answer:
D) all of the above
Question 14.
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
Question 15.
The most important safety method used for protecting home appliances from short circuiting or overloading is
A) earthing
B) use of fuse
C) use of stabilizers
D) use of an electric meter
Answer:
B) use of fuse
Question 16.
What should be the core of an electromagnet ?
A) soft iron
B) hard iron
C) rusted iron
D) none of the above
Answer:
A) soft iron
Question 17.
By increasing the number of turns 3 times in a toroidal solenoid, the magnetic field
A) will become three times
B) will remain unchanged
C) will reduce to one-third
D) none of these
Answer:
A) will become three times
Question 18.
A soft iron bar is introduced inside a current carrying solenoid. The magnetic field inside the solenoid
A) no change
B) will decrease
C) will increase
D) uncertain
Answer:
C) will increase
Question 19.
Inside a current carrying solenoid the magnetic lines of force are
A) circular and do not intersect
B) along the axis of the solenoid and parallel to each other
C) perpendicular to the axis of the solenoid.
D) none of these
Answer:
B) along the axis of the solenoid and parallel to each other
Question 20.
The material of the core of a strong electromagnet is
A) steel
B) soft iron
C) wrought iron
D) brass
Answer:
B) soft iron
Question 21.
A constant current flows in a horizontal wire in the plane of the paper from East to West as shown in figure. The direction of magnetic field at a point will be North and South.
A) directly above the wire
B) directly below the wire
C) at a point located in the plane of the paper, on the north side of the wire
D) at a point located in the plane of the paper, on the south side of the wire.
Answer:
B) directly below the wire
Question 22.
If the key ( K ) in the arrangement (figure) is taken out (i.e., circuit is made open) and the magnetic field lines are drawn over the horizontal plane A B C D, the lines are
A) concentric circles
B) elliptical in shapes
C) straight lines parallel to each other
D) concentric circles near the point O but of elliptical shapes as we go away from it
Two statements are given below as Assertion (A) and Reason (R). Read the statements and choose the correct option.
Answer:
C) straight lines parallel to each other
Question 23.
Assertion (A) : On changing the direction of flow of current through a straight conductor, the direction of a magnetic field around the conductor is reversed. ( )
Reason (R) : The direction of magnetic field around a conductor can be given in accordance with left hand thumb rule.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A.
C) A is true but R is false.
D) A is false but R is true.
Answer:
C) A is true but R is false.
Question 24.
Assertion (A) : A wire carrying current differ from a wire which carries no current
Reason (R) : A magnetic field generated only around current carrying conductors.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A.
C) A is true but R is false.
D) A is false but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.
Question 25.
Assertion (A) : When the direction of velocity of moving charge is perpendicular to the magnetic field, it experience a maximum force
Reason (R) : Force on the moving charge does not depends on the direction magnetic field in which it moves.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A.
C) A is true but R is false.
D) A is false but R is true.
Answer:
C) A is true but R is false.
Question 26.
Assertion (A) : Fuse is safety device which is installed to prevent electrical circuits and possible fires
Reason (R) : Fuse having low melting point, which melts and breaks the circuit if the current exceeds a safe value.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A.
C) A is true but R is false.
D) A is false but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.
Question 27.
Assertion (A) : It is easier to bring North pole of a magnet to South pole of other magnet
Reason ( R ) : There is a force of attraction between unlike poles of magnet.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A.
C) A is true but R is false.
D) A is false but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.
Question 28.
Assertion (A) : The magnetic field inside a solenoid is uniform.
Reason (R) : The magnetic field lines inside a solenoid are parallel.
A) Both A and R are true and R is the correct explanation of A.
B) Both A and R are true but R is not the correct explanation of A
C) A is true but R is false.
D) A is false but R is true.
Answer:
A) Both A and R are true and R is the correct explanation of A.
Question 29.
The correct pattern of magnetic field lines of the field produced by a current carrying circular loop is :
Answer:
(C)
Question 30.
The magnetic field inside a long straight current carrying solenoid :
A) is zero
B) decreases as we move towards its end
C) increases as we move towards its end
D) is same at all points
Answer:
D) is same at all points
Question 31.
An alpha particle enters a uniform magnetic field as shown. The direction of force experienced by the alpha particle is :
A) towards right
B) towards left
C) into the page
D) out of the page
Answer:
D) out of the page
Question 32.
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 centered on the wire.
Answer:
A) The field consists of straight lines perpendicular to the wire.
Question 33.
When is the force experienced by a current-carrying conductor placed in a magnetic field largest ?
A) When the magnetic field is perpendicular to the conductor.
B) When the magnetic field is parallel to the conductor.
C) When the conductor is stationary.
D) When the conductor is made of iron.
Answer:
A) When the magnetic field is perpendicular to the conductor.
Question 34.
Which of the following statements is incorrect ?
A) The field at the center of a long circular coil carrying current consists of parallel straight lines.
B) An electric short circuit occurs when the live wire and the neutral wire come into direct contact.
C) The direction of the magnetic field produced around a straight conductor-carrying current can be determined using the right-hand thumb rule.
D) The function of an earth wire is to prevent the flow of unduly high electric current in the circuit.
Answer:
B) An electric short circuit occurs when the live wire and the neutral wire come into direct contact.
Question 35.
What is the correct sequence of steps to observe the magnetic field around a magnet using a compass ?
A) i) Place the compass near the north pole of the magnet
ii) Mark the position of the needle
iii) Move the needle to a new position
iv) Mark the position of the needle again.
B) i) Place the compass near the south pole of the magnet
ii) Mark the position of the needle
iii) Move the needle to a new position
iv) Mark the position of the needle again.
C) i) Place the compass anywhere on the magnet
ii) -Mark the position of the needle
iii) Move the compass to a new position
iv) Mark the position of the needle again.
D) i) Place the compass near the north pole of the magnet
ii) Mark the position of the needle
iii) Move the compass to a new position
iv) Mark the position of the needle again.
Answer:
(D)
Question 36.
What is the correct sequence of events when metallic appliances are earthed ?
A) i) To prevent electric short circuit
ii) protect the circuits
iii) connect earth wire to metallic body
iv) ensure user safety.
B) i) To ensure user safety
ii) connect earth wire to metallic-body
iii) prevent electric short circuit
iv) protect the circuits.
C) i) Connect earth wire to metallic body
ii) protect the circuits
iii) ensure user safety
iv) prevent electric short circuit.
D) i) Protect the circuits
ii) connect earth wire to metallic body
iii) prevent electric short circuit
iv) ensure user safety.
Answer:
(C)
Question 37.
Which of the following is the odd one out?
A) Magnetic field produced by a solenoid
B) Magnetic field produced by a circular loop
C) Magnetic field produced by a straight conductor-carrying current
D) Magnetic field produced by an electric fuse
Answer:
D) Magnetic field produced by an electric fuse
Question 38.
Assertion : The strength of the magnetic field produced by a current-carrying conductor depends on the closeness of the magnetic field lines.
Reason : The closer the magnetic field lines, the stronger the magnetic field.
A) Both assertion and reason are true and reason is the correct explanation of assertion.
B) Both assertion and reason are true but reason is not the correct explanation of assertion.
C) Assertion is true but reason is false.
D) Both assertion and reason are false.
Answer:
A) Both assertion and reason are true and reason is the correct explanation of assertion.
Question 39.
Assertion: The force experienced by a current-carrying conductor placed in a magnetic field is largest when the direction of the conductor is parallel to the magnetic field lines.
Reason: When the conductor is parallel to the magnetic field lines, the force exerted on it is maximum.
A) Both assertion and reason are true and reason is the correct explanation of assertion.
B) Both assertion and reason are true but reason is not the correct explanation of assertion.
C) Assertion is true but reason is false.
D) Both assertion and reason are false.
Answer:
A) Both assertion and reason are true and reason is the correct explanation of assertion.