JEE Questions for Physics Electromagnetic Induction Quiz 9 - MCQExams.com

A highly conducting ring of radius R is perpendicular to and concentric with the axis of a long solenoid as shown in fig. The ring has a narrow gap of width din its circumference. The solenoid has cross-sectional area A and a uniform internal field of magnitude B0. Now beginning at t = 0, the solenoid current is steadily increased so that the field magnitude at any time t is given by B(t) = B0 + αt where α > 0. Assuming that no charge can flow across the gap, the end of ring which has excess of positive charge and the magnitude of induced e.m.f. in the ring are respectively
Physics-Electromagnetic Induction-69089.png
  • X, Aα
  • X, πR2 α
  • Y, πA2 α
  • Y, πR2 α
Plane figures made of thin wires of resistance R = 50 milli ohm/metre are located in a uniform magnetic field perpendicular into the plane of the figures and which decrease at the rate dB / dt = 0.1 m T / s. The current in the inner and outer boundary are Inner radius a = 10 cm and outer radius b = 20 cm
Physics-Electromagnetic Induction-69091.png
  • 10–4A (Clockwise), 2 × 104 A (Clockwise)
  • 10–4A (Anticlockwise), 2 × 10–4A (Clockwise)
  • 2 × 10–4A (Clockwise), 10–4A (Anticlockwise)
  • 2 × 10–4A (Anticlockwise), 10–4A (Anticlockwise)
A rectangular loop with a sliding connector of length l = 1.0 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r = 2 Ω. Two resistors of 6 Ω and 3 Ω are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v = 2m/s is
Physics-Electromagnetic Induction-69093.png
  • 6 N
  • 4 N
  • 2 N
  • 1 N
A wire cd of length l and mass m is sliding without friction on conducting rails ax and by as shown. The vertical rails are connected to each other with a resistance R between a and b. A uniform magnetic field B is applied perpendicular to the plane abcd such that cd moves with a constant velocity of
Physics-Electromagnetic Induction-69095.png

  • Physics-Electromagnetic Induction-69096.png
  • 2)
    Physics-Electromagnetic Induction-69097.png

  • Physics-Electromagnetic Induction-69098.png

  • Physics-Electromagnetic Induction-69099.png

Physics-Electromagnetic Induction-69101.png

  • Physics-Electromagnetic Induction-69102.png
  • 2)
    Physics-Electromagnetic Induction-69103.png

  • Physics-Electromagnetic Induction-69104.png

  • Physics-Electromagnetic Induction-69105.png
Three solenoid coils of same dimension, same number of turns and same number of layers of windings are taken. Coil 1 with inductance L1 are would using a Mn wire of resistance 11 Ω /µ, coil 2 with inductance L2 was wound using the similar wire but the direction of winding was reversed in each layer, coil 3 with inductance L3 was would using a superconducting wire. The self-inductance of the coils L1, L2, L3 are
  • L1 = L2 = L3
  • L1 = L2 ; L3 = 0
  • L1 = L3 ; L2 = 0
  • L1 > L2 > L3
What is the mutual inductance of a two-loop system as shown with centre separation l?
Physics-Electromagnetic Induction-69108.png

  • Physics-Electromagnetic Induction-69109.png
  • 2)
    Physics-Electromagnetic Induction-69110.png

  • Physics-Electromagnetic Induction-69111.png

  • Physics-Electromagnetic Induction-69112.png
The figure shows three circuits with identical batteries inductors, and resistors, rank the circuits, in the decreasing order, according to the current through the batter (i) just after the switch is dosed and (ii) a long time later
Physics-Electromagnetic Induction-69114.png

  • Physics-Electromagnetic Induction-69115.png
  • 2)
    Physics-Electromagnetic Induction-69116.png

  • Physics-Electromagnetic Induction-69117.png

  • Physics-Electromagnetic Induction-69118.png
The network shown in the figure is part of a complete circuit. If at a certain instant the current i is 5 A and is decreasing at the rate of 103 A / s then VA – VB is
Physics-Electromagnetic Induction-69120.png
  • 5 V
  • 10V
  • 15V
  • 20 V
A 50 volt potential difference is suddenly applied to a coil with L = 5 × 10–3 henry and R =180 ohm. The rate of increase of current after 0.001 second is
  • 27.3 amp/sec
  • 27.8 amp/sec
  • 2.73 amp/sec
  • None of these
The current in a LR circuit builds up to 3/4th of its steady state value in 4s. The time constant of this circuit is

  • Physics-Electromagnetic Induction-69123.png
  • 2)
    Physics-Electromagnetic Induction-69124.png

  • Physics-Electromagnetic Induction-69125.png

  • Physics-Electromagnetic Induction-69126.png
A simple pendulum with bob of mass m and conducting wire of length L swings under gravity through an angle 2 θ. The earth\'s magnetic field component in the direction perpendicular to swing is B. Maximum potential difference induced across the pendulum is
Physics-Electromagnetic Induction-69128.png

  • Physics-Electromagnetic Induction-69129.png
  • 2)
    Physics-Electromagnetic Induction-69130.png

  • Physics-Electromagnetic Induction-69131.png

  • Physics-Electromagnetic Induction-69132.png
An inductor (L = 100 mH), a resistor (R = 100 Ω) and a battery (E = 100V) are initially connected in series as shown in the figure. After a long time the battery is disconnected after short circuiting the points A and B. The current in the circuit 1 ms after the short circuit is
Physics-Electromagnetic Induction-69134.png
  • e A
  • 0.1 A
  • 1 A
  • 1 / e A
A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil it starts oscillating, it is very difficult to stop. But if an aluminum plate is placed near to the coil, it stops. This is due to
  • Development of air current when the plate is placed
  • Induction of electrical charge on the plate
  • Shielding of magnetic lines of force as aluminum is a paramagnetic material
  • Electromagnetic induction in the aluminium
The graph shows the variation in magnetic flux ɸ(t) with time through a coil. Which of the statements given below is not correct
Physics-Electromagnetic Induction-69137.png
  • There is a change in the direction as well as magnitude of the induced e.m.f. between B and D
  • The magnitude of the induced e.m.f. is maximum between B and C
  • There is a change in the direction as well as magnitude of induced e.m.f. between A and C
  • The induced e.m.f. is not zero at B
The variation of induced e.m.f. (E) with time (t) in a coil if a short bar magnet is moved along its axis with a constant velocity is best represented as

  • Physics-Electromagnetic Induction-69139.png
  • 2)
    Physics-Electromagnetic Induction-69140.png

  • Physics-Electromagnetic Induction-69141.png

  • Physics-Electromagnetic Induction-69142.png
The current through a 4.6 H inductor is shown in the following graph. The induced e.m.f. during the time interval t = 5 milli-sec to 6 milli-sec will be
Physics-Electromagnetic Induction-69143.png
  • 103 V
  • –23 × 103 V
  • 23 × 103 V
  • Zero
An alternating current of frequency 200 rad/sec and peak value 1A as shown in the figure, is applied to the primary of a transformer. If the coefficient of mutual induction between the primary and the secondary is 1.5 H, the voltage induced in the secondary will be
Physics-Electromagnetic Induction-69145.png
  • 300 V
  • 191 V
  • 220 V
  • 471 V
A horizontal loop abcd is moved across the pole pieces of a magnet as shown in fig. with a constant speed v. When the edge ab of the loop enters the pole pieces at time t = 0 sec, which one of the following graphs represents correctly the induced e.m.f. in the coil
Physics-Electromagnetic Induction-69147.png

  • Physics-Electromagnetic Induction-69148.png
  • 2)
    Physics-Electromagnetic Induction-69149.png

  • Physics-Electromagnetic Induction-69150.png

  • Physics-Electromagnetic Induction-69151.png
Some magnetic flux is changed from a coil of resistance 10 ohm. As a result an induced current is developed in it, which varies with time as shown in figure. The magnitude of change in flux through the coil in webers is
Physics-Electromagnetic Induction-69152.png
  • 2
  • 4
  • 6
  • None of these
The graph gives the magnitude B(t) of a uniform magnetic field that exists throughout a conducting loop, perpendicular to the plane of the loop. Rank the five regions of the graph according to the magnitude of the e.m.f. induced in the loop, greatest first
Physics-Electromagnetic Induction-69154.png
  • b > (d = e) < (a = c)
  • b > (d = e) > (a = c)
  • b < d < e < c < a
  • b > (a = c) > (d = e)
Figure (i) shows a conducting loop being pulled out of a magnetic field with a speed v. Which of the four plots shown in figure (ii) may represent the power delivered by the pulling agent as a function of the speed v
Physics-Electromagnetic Induction-69156.png
  • a
  • b
  • c
  • d
A rectangular loop is being pulled at a constant speed v, through a region of certain thickness d, in which a uniform magnetic field B is set up. The graph between position x of the right hand edge of the loop and the induced e.m.f. E will be
Physics-Electromagnetic Induction-69158.png

  • Physics-Electromagnetic Induction-69159.png
  • 2)
    Physics-Electromagnetic Induction-69160.png

  • Physics-Electromagnetic Induction-69161.png

  • Physics-Electromagnetic Induction-69162.png
The current i in an inductance coil varies with time t according to the graph shown in fig. Which one of the following plots shows the variation of voltage in the coil with time
Physics-Electromagnetic Induction-69164.png

  • Physics-Electromagnetic Induction-69165.png
  • 2)
    Physics-Electromagnetic Induction-69166.png

  • Physics-Electromagnetic Induction-69167.png

  • Physics-Electromagnetic Induction-69168.png
When a battery is connected across a series combination of self-inductance L and resistance R, the variation in the current i with time t is best represented by

  • Physics-Electromagnetic Induction-69169.png
  • 2)
    Physics-Electromagnetic Induction-69170.png

  • Physics-Electromagnetic Induction-69171.png

  • Physics-Electromagnetic Induction-69172.png
When a certain circuit consisting of a constant e.m.f. E, an inductance L and a resistance R is closed, the current in it increases with time according to curve 1. After one parameter (E, L or R) is changed, the increase in current follows curve 2 when the circuit is closed second time. Which parameter was changed and in what direction
Physics-Electromagnetic Induction-69174.png
  • R is increased
  • L is increased
  • L is decreased
  • R is decreased
A flexible wire bent in the form of a circle is placed in a uniform magnetic field perpendicular to the plane of the coil. The radius of the coil changes as shown in figure. The graph of induced e.m.f. in the coil is represented by
Physics-Electromagnetic Induction-69176.png

  • Physics-Electromagnetic Induction-69177.png
  • 2)
    Physics-Electromagnetic Induction-69178.png

  • Physics-Electromagnetic Induction-69179.png

  • Physics-Electromagnetic Induction-69180.png
The current i in an induction coil varies with time t according to the graph shown in figure. Which of the following graphs shows the induced e.m.f. (e) in the coil with time
Physics-Electromagnetic Induction-69182.png

  • Physics-Electromagnetic Induction-69183.png
  • 2)
    Physics-Electromagnetic Induction-69184.png

  • Physics-Electromagnetic Induction-69185.png

  • Physics-Electromagnetic Induction-69186.png
In a L – R circuit connected to a battery the rate at which energy is stored in the inductor is plotted against time during the growth of the current in the circuit. Which of the following best represents the resulting curve?

  • Physics-Electromagnetic Induction-69188.png
  • 2)
    Physics-Electromagnetic Induction-69189.png

  • Physics-Electromagnetic Induction-69190.png

  • Physics-Electromagnetic Induction-69191.png
Switch S of the circuit shown in figure is closed at t = 0. If e denotes the induced z e.m.f. in L and i the current flowing through the circuit at time t, which of the following graph is correct
Physics-Electromagnetic Induction-69193.png

  • Physics-Electromagnetic Induction-69194.png
  • 2)
    Physics-Electromagnetic Induction-69195.png

  • Physics-Electromagnetic Induction-69196.png

  • Physics-Electromagnetic Induction-69197.png
For previous objective, which of the following graphs is correct e

  • Physics-Electromagnetic Induction-69198.png
  • 2)
    Physics-Electromagnetic Induction-69199.png

  • Physics-Electromagnetic Induction-69200.png

  • Physics-Electromagnetic Induction-69201.png
A square loop of side 5 cm enters a magnetic field with 1 cms–1 . The front edge enters the magnetic field at t = 0 then which graph best depicts e.m.f.
Physics-Electromagnetic Induction-69203.png

  • Physics-Electromagnetic Induction-69204.png
  • 2)
    Physics-Electromagnetic Induction-69205.png

  • Physics-Electromagnetic Induction-69206.png

  • Physics-Electromagnetic Induction-69207.png
Two different coils have self-inductance, L1 = 8mH, L2 = 2mH. The current in one coil is increased at a constant rate. The current in the second coil is also increased at the same rate. At a certain instant of time, the power given to the two coils is the same. At that time the current, the induced voltage and the energy stored in the first coil are i1, V1 and W1 respectively. Corresponding values for the second coil at the same instant are i2, V2 and W2 respectively. Then

  • Physics-Electromagnetic Induction-69209.png
  • 2)
    Physics-Electromagnetic Induction-69210.png

  • Physics-Electromagnetic Induction-69211.png

  • Physics-Electromagnetic Induction-69212.png
The SI unit of inductance, henry, can be written as
  • Weber/ampere
  • Volt-second/ampere
  • Joule/(ampere)2
  • Ohm-second
  • All the above
A field line is shown in the figure. This field cannot represent
Physics-Electromagnetic Induction-69214.png
  • Magneto static field
  • Electrostatic field
  • Induced electric field
  • Gravitational field
Two metallic rings A and B, identical in shape and size but having different resistivities ρA and ρB are kept on top of two identical solenoids as shown in the figure. When current I is switched on in both the solenoids in identical manner, the rings A and B jump to heights hA and hB, respectively, with hA > hB. The possible relation(s) between their resistivities and their masses mA and mB is (are)
Physics-Electromagnetic Induction-69215.png
  • ρA > ρB and mA = mB
  • ρA < ρB and mA = mB
  • ρA > ρB and mA > mB
  • ρA < ρB and mA < mB
A current carrying infinitely long wire is kept along the diameter of a circular wire loop, without touching it. The correct statement (s) is (are)
  • The e.m.f. induced in the loop is zero if the current is constant
  • The e.m.f. induced in the loop is finite if the current is constant
  • The e.m.f. induced in the loop is zero if the current decreases at a steady rate
  • The e.m.f. induced in the loop is finite if the current decreases at a steady rate
A long circular tube of length 10 m and radius 0.3 m carries a current I long its curved surface as shown. A wire-loop of resistance 0.005 ohm and of radius 0.1 m is placed inside the tube with its axis coinciding with the axis of the tube. The current varies as I = 10 cos (300t) where I0 is constant. If the magnetic moment of the loop is N µ0I0 sin (300t), then \'N\' is
Physics-Electromagnetic Induction-69218.png
  • 6
  • 1
  • 2
  • 3
Column I gives certain situations in which a straight metallic wire of resistance R is used and Column II gives some resulting effects. Match the statements in Column I with the statements in Column II
Physics-Electromagnetic Induction-69220.png

  • Physics-Electromagnetic Induction-69221.png
  • 2)
    Physics-Electromagnetic Induction-69222.png

  • Physics-Electromagnetic Induction-69223.png

  • Physics-Electromagnetic Induction-69224.png
Match the following columns
Physics-Electromagnetic Induction-69225.png

  • Physics-Electromagnetic Induction-69226.png
  • 2)
    Physics-Electromagnetic Induction-69227.png

  • Physics-Electromagnetic Induction-69228.png

  • Physics-Electromagnetic Induction-69229.png
Assertion Eddy current is produced in any metallic conductor when magnetic flux is changed around it.
Reason Electric potential determines the flow of charge
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion The quantity L / R possesses dimensions of time.
Reason To reduce the rate of increase of current through a solenoid, we should increase the time constant (L / R).
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion Faraday\'s laws are consequence of conservation of energy.
Reason In a purely resistive ac circuit, the current lags behind the e.m.f. in phase.
  • If both Assertion and Reason are ture and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion Only a change in magnetic flux will maintain an induced current the coil.
Reason The presence of large magnetic flux through a coil maintains a current in the coil if the circuit is continuous.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion In electric circuits, wires carrying currents in opposite directions are often twisted together.
Reason If the wires are not twisted together, the combination of the wires forms a current loop, The magnetic field generated by the loop might affect adjacent circuits or components
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
A circular coil and a bar magnet placed near by are made by move in the same direction. The coil covers a distance of 1 m in 0.5 sec and the magnet a distance of 2 m in 1 sec. The induced e.m.f. produced in the coil
  • Zero
  • 1V
  • 0.5 V
  • Cannot be determined from the given information
A wheel with ten metallic spokes each 0.50 m long is rotated with a speed of 120 rev/min in a plane normal to the earth\'s magnetic field at the place. If the magnitude of the field is 0.4 gauss, the induced e.m.f. between the axle and the rim of the wheel is equal to
  • 1.256 × 10–3 V
  • 6.28 × 10–4 V
  • 1.256 × 10–4 V
  • 6.28 × 10–5 V
Assertion The induced e.m.f. and current will be same in two identical loops of copper and aluminium when rotated with same speed in the same magnetic field.
Reason Induced e.m.f. is proportional to rate of change of magnetic field while induced current depends on resistance of wire.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion Inductance coil are made of copper.
Reason Induced current is more in wire having less resistance.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion Self-inductance is called the inertia of electricity.
Reason Self-inductance is the phenomenon, according to which an opposing induced e.m.f. is produced in a coil as a result of change in current or magnetic flux linked in the coil.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
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