Multiple Choice Questions
Magnetic Effects of Electric Current
Practice Questions with Answers
Total 132 questions available
Q. 1
The strength of magnetic field inside a long
current-carrying straight solenoid is :
A
More at the ends then at the centerB
Minimum in the middleC
Found to increase from one end to the anotherD
Same at all pointsClick an option to check your answer
Q. 2
Commercial electric motors do not use:
A
Effectively large number of conducting wire in the current carrying coilB
A permanent magnet to rotate the armatureC
A soft iron core on which the coil is woundD
An, electromagnetic to rotate the armatureClick an option to check your answer
Q. 3
Electric power is transmitted over long distance through conducting wires at very high voltage because :
A
Relative strength of magnetic field is shown by the degree of closeness of the field linesB
High voltage can be stepped down to desired levels easilyC
Magnetic field lines are closed curvesD
The power losses are reduced to minimumClick an option to check your answer
Q. 4
Where do magnetic field lines originate and terminate in a magnet?
A
They originate from the south pole and terminate at the north poleB
They originate from the north pole and terminate at the south poleC
They originate from the center of the magnetD
They terminate at the center of the magnetClick an option to check your answer
Q. 5
A small magnet is placed perpendicular to a uniform magnet field. The forces acting on the magnet will result in
A
ClockwiseB
Rotational motionC
Translatory motionD
Towards southClick an option to check your answer
Q. 6
The magnetic field is the strongest at
A
both poles.B
North poleC
East poleD
south pole.Click an option to check your answer
Q. 7
Which of the following determines the direction of magnetic field due to a current carrying conductor?
A
Maxwell’s cork screw-ruleB
Faraday’s laws of electromagnetic inductionC
Fleming’s left-hand ruleD
Heating effect of currentClick an option to check your answer
Q. 8
What is the behavior of a compass when it moves around a magnetic field line?
A
It remains stationaryB
It spins rapidlyC
It vibratesD
It aligns itself along the direction of the magnetic field lineClick an option to check your answer
Q. 9
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
AnticlockwiseB
UpwardsC
ClockwiseD
Towards southClick an option to check your answer
Q. 10
What does the magnitude of induced emf not depend on when a magnet is inserted into a coil?
A
The number of turns in the coil.B
The speed at which the magnet is moved.C
The material's resistivity of the coil.D
The strength of the magnetClick an option to check your answer
Q. 11
Who is credited with accidentally discovering the relationship between electricity and magnetism?
A
Thomas EdisonB
Albert EinsteinC
Isaac NewtonD
Hans Christian OerstedClick an option to check your answer
Q. 12
What tool detects magnetic fields at a location?
A
Powerful magnetB
Coiled wireC
Compass needleD
Wire carrying electricityClick an option to check your answer
Q. 13
What is the path traced by the north pole pointer of a compass under the influence of a magnetic field called?
A
Magnetic routeB
Magnetic lineC
Field trailD
Magnetic field lineClick an option to check your answer
Q. 14
What produces a magnetic field around a current-carrying wire?
A
MagnetismB
ElectricityC
HeatD
LightClick an option to check your answer
Q. 15
The direction of force acting on a current carrying conductor placed in a magnetic field can be obtained by:
A
Ampere's swimming rule.B
Clock face rule.C
Fleming's left hand rule.D
Fleming's right hand rule.Click an option to check your answer
Q. 16
Birds do not feel electric shock while sitting on a current carrying uninsulated wires because :
A
In horizontal as well as in vertical planes around the magnetB
The feathers of birds act as an insulator and hence current does not pass through themC
The potential difference between the two claws of birds is very smallD
The current does not pass through the body as the claws of birds are non-conductingClick an option to check your answer
Q. 17
At the time of short circuit, the current in the
circuit:
A
Increases heavilyB
Vary continuouslyC
Does not changeD
Reduces substantiallyClick an option to check your answer
Q. 18
AC generator works on the principle of
A
faraday’s law of electromagnetic induction.B
ohnis lawC
Joule’s law of heatingD
none of the aboveClick an option to check your answer
Q. 19
A strong bar magnet is placed vertically above a horizontal wooden board. The magnetic lines of force will be:
A
In horizontal as well as in vertical planes around the magnetB
In all planes around the magnetC
Only in vertical plane around the magnetD
Only in horizontal plane around the magnetClick an option to check your answer
Q. 20
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current change once in each
A
half revolutionB
two revolutionsC
One rotationD
One-fourth rotationClick an option to check your answer
Q. 21
Which statement about magnetic field lines is wrong?
A
The field lines go from North to South inside the magnet.B
The density of field lines indicates the strength of the magnet.C
The field is tangent to the magnetic field line.D
Magnetic field lines form closed and continuous curves.Click an option to check your answer
Q. 22
How many fundamental forces in nature are commonly known?
A
TwoB
ThreeC
FourD
FiveClick an option to check your answer
Q. 23
The strength of an electromagnet after the limit
cannot be increased by increasing the current
through the solenoid. What is the reason behind
this phenomenon?
A
Resistance of the solenoid increases.B
Electrons start to corrode the solenoid.C
Voltage through the solenoid gradually starts to decrease.D
Current flowing through the solenoid is saturated.Click an option to check your answer
Q. 24
Which of the following is not true
A
We cannot isolate a single poleB
We can magnetise an iron ringC
A permanent magnet retains its magnetism even when heated on a flame.D
Increasing the size of the gap in which the armature turnsClick an option to check your answer
Q. 25
Unit of (a) (c) is :
A
FlemingB
evC
AmpereD
FaradClick an option to check your answer
Q. 26
Which of the following combination is not correct ?
A
Electric generator-Electromagnetic inductionB
Compass Needle-Small MagnetC
Electric Motor-Fleming's right hand ruleD
Earth wire-Green colourClick an option to check your answer
Q. 27
Which of the following determine the direction
of magnetic field due to a current carrying
conductor?
A
Lenz's lawB
Maxwell's cork screw-ruleC
Fleming's left hand ruleD
Faraday's laws of electromagnetic inductionClick an option to check your answer
Q. 28
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 eastB
downwardC
towards southD
upwardClick an option to check your answer
Q. 29
What is responsible for the generation of current?
A
Static chargeB
Motion of chargesC
Magnetic field strengthD
Size of the conductorClick an option to check your answer
Q. 30
The mains power supply of a house is through a 2A fuse. How many 50W bulbs can be used in this house at the normal voltage?
A
5B
8C
9D
6Click an option to check your answer
Q. 31
Magnetic effect of current was discovered by
A
MCDB
BohrC
MotorD
OerstedClick an option to check your answer
Q. 32
What is induced emf or current directly proportional to?
A
The rate of change in the magnetic fieldB
The resistance of the wireC
The length of the wireD
The strength of the magnetic fieldClick an option to check your answer
Q. 33
A bar magnet is immersed in a heap of iron
fillings and pulled out. The amount of iron filling
clinging to the:
A
Magnet will be same all along its lengthB
North pole is almost equal to the South poleC
North pole is much more than the South PoleD
North pole is almost less equal than the South poleClick an option to check your answer
Q. 34
What happens to magnetic field lines?
A
They cross each other at right angles.B
They cross each other at a 45-degree angle.C
They cross each other at a 60-degree angle.D
They never cross each other.Click an option to check your answer
Q. 35
What is needed for electromagnetic induction to occur?
A
The galvanometer must move relative to the wire coil.B
The wire coil must move relative to a magnet.C
The galvanometer must move relative to a magnet.D
The galvanometer must move relative to an electric motor.Click an option to check your answer
Q. 36
How does the direction of the thumb in Fleming's left-hand rule relate to the motion of the charge?
A
It indicates the direction of the magnetic fieldB
It indicates the direction of the currentC
It indicates the direction of the forceD
It indicates the direction of the chargeClick an option to check your answer
Q. 37
Metal which can be used for construction of base of magnetic compass is :
A
NickelB
AluminiumC
CobaltD
IronClick an option to check your answer
Q. 38
The direction of magnetic field around a straight conductor carrying current can be determined by
A
Lenz’s lawB
Right hand thumb ruleC
A compass needleD
South-northClick an option to check your answer
Q. 39
By removing the inducing magnets, the induced
magnetism is:
A
Not ChargedB
Finished just afterC
Finished after sometimeD
Non-finished for a long timeClick an option to check your answer
Q. 40
Commercial motors do not use:
A
an electromagnet to rotate the armatureB
effectively large number of turns of conducting wire in the current carrying coilC
a permanent magnet to rotate the armatureD
a soft iron core on which the coil is woundClick an option to check your answer
Q. 41
The core of electromagnet is made of:
A
copperB
magnesiumC
soft ironD
steelClick an option to check your answer
Q. 42
The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer. The magnet was held stationary for a few seconds with the North pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was:
A
At rest inside the solenoidB
Moving out of the solenoidC
Moving into the solenoidD
Moving towards the solenoidClick an option to check your answer
Q. 43
A 3 pin mains plug is fitted to the cable for a 1 kW
electric kettle to be used on a 250 V a.c. supply
which of the following statements is not correct?
A
A 13 A fuse is the most appropriate value to use.B
The fuse should be fitted in the live wire.C
The neutral wire is coloured black.D
The green wire should be connected to the earth pin.Click an option to check your answer
Q. 44
What determines the direction of induced current in a conductor?
A
The material of the conductorB
The temperature of the conductorC
The direction of relative motion between the conductor and magnetic fieldD
The size of the conductorClick an option to check your answer
Q. 45
How does a compass align itself when moved around a magnetic field line?
A
It points straight downB
It points straight upC
It aligns tangentially along the curves of the magnetic field lineD
It spins in circlesClick an option to check your answer
Q. 46
The magnetic field inside the solenoid is:
A
zeroB
same at all pointsC
variableD
non-uniformClick an option to check your answer
Q. 47
How many magnetic poles are there in a current carrying solenoid?
A
twoB
nineC
tenD
fourClick an option to check your answer
Q. 48
What factors determine the magnitude of force experienced by a charge moving in a magnetic field?
A
Color and size of the chargeB
Velocity and strength of the magnetic fieldC
Temperature and pressure of the chargeD
Shape and texture of the chargeClick an option to check your answer
Q. 49
What causes a current-carrying conductor to experience a force when near a magnet?
A
The magnet's temperatureB
The magnet's colorC
The magnet's sizeD
The magnet's magnetic fieldClick an option to check your answer
Q. 50
What happens to a small compass near a magnet?
A
It becomes smallerB
It experiences a forceC
It stops workingD
It changes colorClick an option to check your answer
Q. 51
Which color wire is used for earthing ?
A
Green or yellowB
yellowC
none of theseD
GreenClick an option to check your answer
Q. 52
What happens to the magnetic field lines when a strong bar magnet is placed vertically above a surface?
A
They only form in a horizontal plane around the magnet.B
They only form in a vertical plane around the magnet.C
They form in both horizontal and vertical planes around the magnet.D
They form in all planes around the magnet.Click an option to check your answer
Q. 53
What is electromagnetism?
A
The study of electric carsB
The study of the relationship between electricity and magnetismC
The study of the Earth's magnetic fieldD
The study of atomic structureClick an option to check your answer
Q. 54
Which of the following instruments works by electromagnetic induction?
A
MotorB
Moving coil galvanometer.C
Dynamo.D
Telephone receiver.Click an option to check your answer
Q. 55
Who has stated the Right hand Thumb Rule?
A
EinsteinB
MaxwellC
AmmeterD
VoltmeterClick an option to check your answer
Q. 56
The phenomenon of electromagnetic induction is:
A
the process of generating magnetic field due to a current passing through a coil.B
producing induced current in a coil due to relative motion between a magnet and the coil.C
the process of rotating a coil of an electric motor.D
the process of charging a body.Click an option to check your answer
Q. 57
The essential difference between an A.C.
generator and a D.C. generator is that:
A
A.C. generator has slip rings while the D.C. generator has a commutator.B
A.C. generator will generate a higher voltage.C
D.C. generator will generate a higher voltage.D
A.C. generator has an electromagnet while a D.C. generator has permanent magnet.Click an option to check your answer
Q. 58
The most important safety method used for
protecting home appliance from short circuiting
on overloading is:
A
use of fuseB
use of stabilizersC
earthingD
use of fuse electric meterClick an option to check your answer
Q. 59
When does induced current flow in a conductor?
A
When the conductor is stationaryB
When the conductor is heatedC
When there are no changes in the magnetic fieldD
When the magnetic field through the conductor changesClick an option to check your answer
Q. 60
What happens to the magnetic field produced by a wire when the current direction is reversed?
A
It stays the sameB
It changes directionC
It gets strongerD
It gets weakerClick an option to check your answer
Q. 61
No force acts on a current carrying conductor when it is placed-
A
The neutral wire is coloured blackB
far away from the magnetic fieldC
parallel to the magnetic fieldD
perpendicular to the magnetic fieldClick an option to check your answer
Q. 62
Which of the following processes will not produce new magnetic poles?
A
running a current through a straight wireB
cutting a bar magnet in halfC
Magnetic effect of currentD
Heating effect of currentClick an option to check your answer
Q. 63
We can induce the current in a coil by
A
by changing the orientation of the coil in the magnetic fieldB
by changing the magnetic field around itC
moving the coil in a magnetic fieldD
Straight conductor carrying currentClick an option to check your answer
Q. 64
If the force exerted on a current carrying wire placed in a magnetic field is zero, then the angle between wire and the direction of magnetic field is
A
75°B
90°C
180°D
150°Click an option to check your answer
Q. 65
Rashita and her friends were decorating the class
bulletin board. She accidentally dropped the
box of stainless steel pins by mistake. She tried
to collect the pins using a magnet. She could not
succeed. Why?
A
Steel pins are very longB
They are not using the magnet in right directionC
Steel is not magnetic in natureD
Steel pins are very heavy and cannot be lifted magnetClick an option to check your answer
Q. 66
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 eastB
TransformerC
upwardD
GalvanometerClick an option to check your answer
Q. 67
Which technologies were later developed based on Oersted's discovery?
A
Airplane and telephoneB
Radio, television, and fibre opticsC
Printing press and steam engineClick an option to check your answer
Q. 68
The strength of magnetic field inside a long
current carrying straight solenoid is:
A
uniform at all points.B
found to increase from one end to the other.C
minimum in the middle.D
more at the ends than at the centre.Click an option to check your answer
Q. 69
If a charged particle moves along a magnetic field line, what happens to the magnetic force on the particle?
A
It goes in the same direction as its movement.B
There is no magnetic force.C
It goes in the opposite direction to its movementD
It goes at a right angle to its movement.Click an option to check your answer
Q. 70
In Fleming's left-hand rule, what does the direction of the thumb represent?
A
The direction of motionB
The flow of electricityC
The direction of the magnetic fieldD
The presence of electric chargeClick an option to check your answer
Q. 71
Induced current flows through a coil
A
for less than the period during which flux changes through it.B
Only in vertical plane around the magnetC
All of theseD
only for the period during which flux changes through it.Click an option to check your answer
Q. 72
The shape of the earth’s magnetic field resembles that of an imaginary:
A
Bar magnetB
Current-carrying circular coilC
Straight conductor carrying currentD
U-shaped magnetClick an option to check your answer
Q. 73
What type of force does electromagnetism study?
A
Electromagnetic forceB
Gravitational forceC
Magnetic forceD
Nuclear forceClick an option to check your answer
Q. 74
A positively-charged particle (alphaparticle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is
A
FaradayB
upwardC
towards eastD
FlemingClick an option to check your answer
Q. 75
Which of the following is not an example of the
right hand thumb rule ?
A
A.C. generatorB
D.C. motorC
SolenoidD
Cartesian coordinate systemClick an option to check your answer
Q. 76
By removing the inducing magnet, the induced magnetism is
A
Does not changeB
Finished just afterC
Not finished for a long timeD
Increases heavilyClick an option to check your answer
Q. 77
If an electron is moving to the right (east) and a magnetic field is pointing downward, in which direction will the magnetic force act?
A
Towards the right (east)B
Towards the left (west)C
Towards the northD
Towards the southClick an option to check your answer
Q. 78
Which one of the following substances is the magnetic substances?
A
OerstedB
SilverC
FlemingD
IronClick an option to check your answer
Q. 79
Which hand is used in Fleming's left-hand rule?
A
Left handB
Right handC
Both handsD
None of the handsClick an option to check your answer
Q. 80
If it takes 520 turns to make a solenoid that is
40 cm long with a radius of 1.2 m that carries a
current of 6 A, then determine the magnetic field
inside the solenoid.
A
9.8 x 10-3TB
8.4 x 10-4TC
10.2 x 10-4TD
7.2 x 10-3 TClick an option to check your answer
Q. 81
A toaster of 4 kW is running in an existing circuit
110 volt that has a stream ranking of 4 A. Find the
stream of electrons drawn by the toaster.
A
9.06 AB
14.6 AC
23.34 AD
36.36 AClick an option to check your answer
Q. 82
The direction of induced current is given by
A
Cross at an angle of 600B
Fleming’s right hand ruleC
Do not cross one anotherD
Right hand thumb ruleClick an option to check your answer
Q. 83
At the time of short circuit , the current in the circuit
A
Vary continuouslyB
PlasticsC
Iron and steelD
Increases heavilyClick an option to check your answer
Q. 84
In normal use, a current of 3.5 A flows through a hair dryer. Choose a suitable fuse from the given:
A
Thirty AB
Three AC
Five AD
Ten AClick an option to check your answer
Q. 85
A finite straight wire carries a current of 3 A, where
it is a 2 m long and weighs around 240 g. If it is
suspended in the mid-air by a uniform magnetic
field then calculate the field B. [Acceleration due
to gravity = 9.8 m/s2]
A
0.42 TB
0.37 TC
0.39 TD
0.61 TClick an option to check your answer
Q. 86
What does Fleming's left-hand rule help determine?
A
Direction of magnetic fieldB
Direction of electric currentC
Direction of temperature changeD
Direction of motionClick an option to check your answer
Q. 87
Current that does not change its direction after equal intervals of time is called:
A
Magnetic effect of currentB
direct currentC
Static electricityD
Chemical effect of currentClick an option to check your answer
Q. 88
A vertical wire carries a current upward. The magnetic field north of the wire will be directed
A
westwardB
upwardC
AmmeterD
VoltmeterClick an option to check your answer
Q. 89
The phenomena of electromagnetic induction is
A
AC generator has an electromagnet while a DC generator has permanent magnetB
AC generator has slip rings while the DC generator has a commutatorC
the process of rotating a coil of an electric motor.D
producing induced current in a coil due to relative motion between a magnet and the coilClick an option to check your answer
Q. 90
How can we observe the effect of a magnetic field on a compass?
A
By listening to soundsB
By feeling heatC
By observing deflection in the compass needleD
By smelling scentsClick an option to check your answer
Q. 91
What can magnetic field lines help us figure out?
A
The shape of the magnetic field.B
Only the direction of the magnetic field.C
Only the relative strength of the magnetic field.D
Both the direction and the relative strength of the magnetic field.Click an option to check your answer
Q. 92
When the bars of bismuth are placed between the magnetic poles they set their length
A
along the lines of forceB
Current-carrying circular coilC
perpendicular to the lines of forceD
Of hike in the supply voltageClick an option to check your answer
Q. 93
Which of the following statement is not correct about two parallel conductors carrying equal currents in the same direction?
A
The process of charging a bodyB
Electrical energy into mechanical energyC
Each of the conductors will repel each other.D
The two conductors will repel each other.Click an option to check your answer
Q. 94
What happened to a compass needle when an electric current passed through a nearby metallic wire?
A
It stayed stillB
It vibratedC
It deflectedD
It brokeClick an option to check your answer
Q. 95
On which of the following does not exert any force when kept in uniform magnetic field?
A
Stationary magnetB
Stationary chargeC
Moving chargeD
Moving magnetClick an option to check your answer
Q. 96
Inside the magnet, the field lines move:
A
away from South polesB
away from North poleC
from South to NorthD
from North to SouthClick an option to check your answer
Q. 97
The most suitable material for making the core of an electromagnet is:
A
GalvanometerB
GeneratorC
SteelD
Soft ironClick an option to check your answer
Q. 98
The north pole of earth magnet is in the:
A
Geographical eastB
Geographical southC
Geographical northD
Geographical westClick an option to check your answer
Q. 99
What is induced current?
A
A current that flows due to changes in a magnetic fieldB
A current that flows in a wire when it carries electricityC
A current that flows in a wire without any sourceD
A current that flows in a wire when it's heatedClick an option to check your answer
Q. 100
The most common device for providing an emf is :
A
GeneratorB
Electric cellC
AmmeterD
All of theseClick an option to check your answer
Q. 101
To avoid risk of electrical shock, which phenomena is used?
A
AmmeterB
EarthingC
Short circuitingD
ClockwiseClick an option to check your answer
Q. 102
The magnetic lines of force, inside a current carrying solenoid, are
A
perpendicular to the axis and equidistance from each otherB
In horizontal as well as in vertical planes around the magnetC
In all planes around the magnetD
along the axis and are parallel to each otherClick an option to check your answer
Q. 103
An electric charge in uniform motion produces
A
both electric and magnetic fieldsB
an electric field onlyC
A stationary electric chargeD
An unmagnetised iron barClick an option to check your answer
Q. 104
The process of inducing a current in a coil of wire
by placing it in a region of changing magnetic
field is:
A
Magnetic effect of currentB
Electromagnetic inductionC
Heating effect of currentD
Electrical effectClick an option to check your answer
Q. 105
Consider the following statements and choose the
correct are:
A
A magnet is an object which attracts pieces of iron, Nickel and cobaltB
The end of a freely suspended magnet which points towards the north direction is called the north pole of the magnetC
A magnet is an object which attracts pieces of
iron, Nickel and cobaltD
All of the aboveClick an option to check your answer
Q. 106
The magnetic field of the current was discovered
by:
A
FlemingB
OerstedC
MaxwellD
FaradayClick an option to check your answer
Q. 107
A tesla is equivalent to a
A
newton per ampere-meterB
newton per ampere-secondC
Electric chargeD
Electric energyClick an option to check your answer
Q. 108
On increasing number of turns magnetic field of a solenoid:
A
West poleB
East poleC
DecreaseD
IncreaseClick an option to check your answer
Q. 109
The strength of magnetic field inside a long current carrying straight solenoid is
A
Geographical westB
same at all pointsC
minimum in the middleD
Geographical eastClick an option to check your answer
Q. 110
Strength of the magnetic field at a point in the
space surrounding the magnet is measured by:
A
resistance of it.B
length of the magnet.C
thickness of the magnet.D
number of lines crossing a given point.Click an option to check your answer
Q. 111
When does a charge experience a force in a magnetic field?
A
When the charge is at restB
When the charge is stationaryC
When the charge is in motionD
When the charge is smallClick an option to check your answer
Q. 112
The touching of the live wire and neutral wire directly is known as :
A
Short circuitB
Over loadingC
One rotationD
None of theseClick an option to check your answer
Q. 113
What causes induced emf or current to increase?
A
A decrease in the rate of change in the magnetic fieldB
An increase in the rate of change in the magnetic fieldC
A decrease in the resistance of the wireD
An increase in the temperature of the wireClick an option to check your answer
Q. 114
Fleming's Right-hand rule gives:
A
Both, direction and magnitude of the induced current.B
Direction of the induced current.C
Magnitude of the magnetic field.D
Magnitude of the induced current.Click an option to check your answer
Q. 115
A magnetic field directed in north direction acts on an electron moving in east direction. The magnetic force on the electron will act
A
vertically downwards.B
vertically upwards.C
VoltmeterD
TransformerClick an option to check your answer
Q. 116
What would change the amount the meter moves when a bar magnet is pushed into a long coil?
A
How quickly the magnet is pushed into the coil.B
The direction the coil is wrapped.C
Which end of the coil the magnet goes into.D
Which pole of the magnet enters the coil first.Click an option to check your answer
Q. 117
Who has stated the Right hand Thumb Rule?
A
EinsteinB
MaxwellC
OrstedD
CircuitClick an option to check your answer
Q. 118
A DC generator is based on the principle of:
A
Magnetic effect of currentB
Heating effect of currentC
Electromagnetic inductionD
Electrochemical inductionClick an option to check your answer
Q. 119
What unit of magnetic field was named after Hans Christian Oersted?
A
NewtonB
TeslaC
OerstedD
JouleClick an option to check your answer
Q. 120
The device used for producing electric current is
called a :
A
MotorB
AmmeterC
GeneratorD
GalvanometerClick an option to check your answer
Q. 121
Which of the following correctly describes the magnetic field near a long straight wire?
A
Circular, but they do not intersect each otherB
The field consists of concentric circles centred on the wire.C
The field consists of straight lines parallel to the wire.D
Circular at the ends inside the solenoidClick an option to check your answer
Q. 122
Which of the following properties of a proton can change while it moves freely in a magnetic field?
A
OerstedB
MaxwellC
Kinetic energy.D
MomentumClick an option to check your answer
Q. 123
What happens to the magnetic lines of force inside a current-carrying solenoid?
A
They are perpendicular to the axis.B
They run along the axis and are parallel to each other.C
They are parallel inside the solenoid and circular at the ends.D
They are circular.Click an option to check your answer
Q. 124
Which one of the following substances is the
magnetic substances?
A
IronB
SilverC
MercuryD
GoldClick an option to check your answer
Q. 125
The magnetic field strength of a solenoid can be
increased by inserting:
A
an iron piece into it.B
a glass piece into it.C
paper roll into it.D
a wooden piece into it.Click an option to check your answer
Q. 126
In Fleming’s right hand rule direction in induced current is given by:
A
middle fingerB
first fingerC
Towards southD
AnticlockwiseClick an option to check your answer
Q. 127
The effective length of the magnet is
A
the half of the length of the magnetB
The field consists of straight lines parallel to the wireC
The field consists of radial lines originating from the wireD
the distance between the two poles of the magnetClick an option to check your answer
Q. 128
The magnetic field lines inside a solenoid are in the form of:
A
Circular linesB
Curved lineC
Parallel straight linesD
Zig-zag linesClick an option to check your answer
Q. 129
The frequency of direct current (DC) is:
A
50 HzB
30 HzC
0 HzD
25 HzClick an option to check your answer
Q. 130
Magnetic field due to a current through a straight conductor depends on
A
AluminiumB
Soft ironC
distance from the wireD
Both (a) and (b)Click an option to check your answer
Q. 131
A TV set consumes an electric power of 230 watts and runs on 230 volts mains supply. The correct fuse for this TV set is:
A
One AB
Two AC
Three AD
Five AClick an option to check your answer
Q. 132
Direction of rotation of a coil in electric motor is determined by
A
faraday law of electromagnetic inductorsB
fleming’s right hand ruleC
fleming’s left hand ruleD
None of aboveClick an option to check your answer
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