# Multiple choice questions on Magnetic Equipments #### Magnetic Equipments Question Bank for JEE Main & Advanced Physics:

Ques: The radius of the coil of a Tangent galvanometer. which has 10 turns is 0.1m. The current required to produce a deflection of 60° (BH = 4 x 10–5 T) is
(a) 3 A
(b) 1.1 A
(c) 2.1 A
(d) 1.5 A
Ans. (b)

Ques: The period of oscillation of a magnet in vibration magnetometer is 2 sec. The period of oscillation of a magnet whose magnetic moment is four times that of the first magnet is
(a) 1 sec
(b) 4 sec
(c) 8 sec
(d) 0.5 sec
Ans. (a)

Related: Solutions (Chemistry) Questions

Ques: In a tangent galvanometer a current of 0.1 A produces a deflection of 30o. The current required to produce a deflection of 60o is
(a) 0.2 A
(b) 0.3 A
(c) 0.4 A
(c) 0.5 A
Ans. (b)

Ques: A bar magnet is oscillating in the earth’s magnetic field with time period T. If its mass is increased four times then its time period will be
(a) 4 T
(b) 2 T
(c) T
(d) T/2
Ans. (b)

Ques: Which of the following statement is not the true
(a) While taking reading of tangent galvanometer, the plane of the coil must be set at right angles to the earth’s magnetic meridian
(b) A short magnet is used in a tangent galvanometer since a long magnet would be heavy and may not easily move
(c) Measurements with the tangent galvanometer will be more accurate when the deflection is around 45o
(d) A tangent galvanometer cannot be used in the polar region
Ans. (a)

Ques: The sensitivity of a tangent galvanometer is increased if
(a) Number of turn decreases
(b) Number of turn increases
(c) Field increases
(d) None of the above
Ans. (b)

Ques: A magnetic needle suspended by a silk thread is vibrating in the earth’s magnetic field. If the temperature of the needle is increased by 500°C, then
(a) The time period decreases
(b) The time period remains unchanged
(c) The time period increases
(d) The needle stops vibrating
Ans. (c)

Ques: Before using the tangent galvanometer, its coil is set in
(a) Magnetic meridian (or vertically north south)
(b) Perpendicular to magnetic meridian
(c) At angle of 45o to magnetic meridian
(d) It does not require any setting
Ans. (a)

Ques: The time period of oscillation of a magnet in a vibration magnetometer is 1.5 seconds. The time period of oscillation of another magnet similar in size, shape and mass but having one-fourth magnetic moment than that of first magnet, oscillating at same place will be
(a) 0.75 sec
(b) 1.5 sec
(c) 3 sec
(d) 6 sec
Ans. (c)

Ques: To measure which of the following, is a tangent galvanometer used
(a) Charge
(b) Angle
(c) Current
(d) Magnetic intensity
Ans. (c)

Ques: The strength of the magnetic field in which the magnet of a vibration magnetometer is oscillating is increased 4 times its original value. The frequency of oscillation would then become
(a) Twice its original value
(b) Four times its original value
(c) Half its original value
(d) One-fourth its original value
Ans. (a)

Ques: The bob of a simple pendulum is replaced by a magnet. The oscillations are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is short-circuited. Then which one of the following happens
(a) Period decreases
(b) Period does not change
(c) Oscillations are damped
(d) Amplitude increases
Ans. (c)

Ques: Which of the following statement is true about magnetic moments of atoms of different elements?
(a) All have a magnetic moment
(b) None has a magnetic moment
(c) All acquire a magnetic moment under external magnetic field and in same direction as the field
(d) None of the above statements are accurate
Ans. (d)

Ques: Tangent galvanometer is used to measure
(b) Current impulses
(c) Magnetic moments of bar magnets
(d) Earth’s magnetic field
Ans. (a)

Ques: A magnetic needle suspended horizontally by an unspun silk fibre, oscillates in the horizontal plane because of the restoring force originating mainly from
(a) The torsion of the silk fibre
(b) The force of gravity
(c) The horizontal component of earth’s magnetic field
(d) All the above factors
Ans. (c)

Ques: In sum and difference method in vibration magnetometer, the time period is more if
(a) Similar poles of both magnets are on same sides
(b) Opposite poles of both magnets are on same sides
(c) Both magnets are perpendicular to each other
(d) Nothing can be said
Ans. (b)

Ques: Keeping dissimilar poles of two magnets of equal pole strength and length same side, their time period will be
(a) Zero
(b) One second
(c) Infinity
(d) Any value
Ans. (c)

Related: Question Paper for AUEET

Ques: Time period of a freely suspended magnet does not depend upon
(a) Length of the magnet
(b) Pole strength of the magnet
(c) Horizontal component of earth’s magnetic field
(d) Length of the suspension thread
Ans. (d)

Ques: Vibration magnetometer before use, should be set
(a) In magnetic meridian
(b) In geographical meridian
(c) Perpendicular to magnetic meridian
(d) In any position
Ans. (a)

Ques: Two short magnets having magnetic moments in the ratio 27 : 8, when placed on opposite sides of a deflection magnetometer, produce no deflection. If the distance of the weaker magnet is 0.12 m from the centre of deflection magnetometer, the distance of the stronger magnet from the centre is
(a) 0.06 m
(b) 0.08 m
(c) 0.12 m
(d) 0.18 m
Ans. (d)

### About the author

#### Richa Bhardwaj

Richa (B. Tech) has keen interest in Science and loves to teach students about it through lectures and assignments. She always try to use simple language and sentences while writing to make sure learner understands everything properly.