Magnetic Effects of Electric Current
Class 10th Science Chapter MCQs
Magnetic Effects of Electric Current Class 10 MCQs Questions
1.
Choose the incorrect statements from the following regarding
magnetic lines of field.
(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.
Answer
Answer: (c) if magnetic field lines are parallel and equidistant, they represent zero field strength
2.
If the key in the arrangement figure given below is taken out
(the circuit is made open) and magnetic . field lines are drawn over the
horizontal plane ABCD, the lines are
(a) concentric circles
(b) elliptical in shape
(c) straight lines parallel
to each other (Due to earth’s magnetic field)
(d) concentric circles near the
point O but of elliptical shapes as we go away from
it.
Answer
Answer: (c) straight lines parallel to each other (Due to earth’s magnetic field)
3.
A circular loop placed in a plane perpendicular to the plane
of paper carries a current when the keys is ON. The current as seen from points
A and B (in the plane of paper and on the axis of the coil) is anticlockwise and
clockwise respectively. The magnetic field lines point from B to A. The N-pole
of the resultant magnet is on the faces 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.
Answer
Answer: (a) A
4.
Magnetic lines of force inside current carrying solenoid
are
(a) perpendicular to axis.
(b) along the axis and are parallel to each
other.
(c) parallel inside the solenoid and circular at the ends.
(d)
circular.
Answer
(c) parallel inside the solenoid and circular at the ends.
5.
What should be the core of an electromagnet?
(a) soft
iron
(b) hard iron
(c) rusted iron
(d) none of
above
Answer
(a) soft iron
6.
Who has stated the Right hand Thumb Rule?
(a) Orsted
(b)
Fleming
(c) Einstein
(d) Maxwell
Answer
(d) Maxwell
7.
The device used for producing electric current is called
(a) generator
(b) galvanometer
(c) ammeter
(d)
motor
Answer
(a) generator
8.
To convert an AC generator into DC generator
(a) split-ring
type commutator must be used
(b) slip rings and brushes must be used
(c) a
stronger magnetic field has to be used
(d) a rectangular wire loop has to be
used
Answer
(a) split-ring type commutator must be used
9.
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 electric
meter
Answer
(b) use of fuse
10.
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
Answer
(d) the direction of magnetic field is vertically upward.
11.
If the current values periodically from zero to a maximum
value, back to zero and then reverses its direction, the current is
(a)
direct
(b) alternative
(c) pulsating
(d) none of the
above
Answer
(b) alternative
12.
We can induce the current in a coil by
(a) moving the coil
in a magnetic field
(b) by changing the magnetic field around it
(c) by
changing the orientation of the coil in the magnetic field
(d) All of
above
Answer
(a) moving the coil in a magnetic field
13.
Forces acting on a stationery charge of in the magnetic field
B is
(a) BQ v
(b) BQ/v
(c) Bv/Q
(d) zero
Answer
(d) zero
14.
A current through a horizontal power line flows from south to
North direction. The direction of magnetic field line 0.5m above it is
(a)
North
(b) South
(c) West
(d) East
Answer
(a) North
15.
A D.C generator works on the principle of
(a) ohnis
law
(b) Joule’s law of heating
(c) faraday’s law of electromagnetic
induction.
(d) none of the above
Answer
(c) faraday’s law of electromagnetic induction.
16.
A soft iron bar is introduced inside the current carrying
solenoid. The magnetic field inside the solenoid
(a) will decrease
(b)
will remains same
(c) will increase
(d) will become
zero
Answer
(c) will increase
17.
In the domestic electric circuits, the red coloured insulated
copper wire is called
(a) Neutral wire
(b) Fuse wire
(c) Live wire
(d) Earthing wire
Answer
(c) Live wire
18.
When current is parallel to magnetic field, then force
experience by the current carrying conductor placed in uniform magnetic field
is
(a) Twice to that when angle is 60°
(b) Thrice to that when angle is
60°
(c) zero
(d) infinite
Answer
(a) Twice to that when angle is 60°
19.
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
(d) All of the above
20.
In electric motor, to make the coil rotating continuously in
the same direction, current is reversed in the coil after every half rotation by
a device called
(a) carbon brush
(b) commutator
(c) slip ring
(d)
armature
Answer
>(b) commutator
21.
A positively charged particle say an alpha particle projected
towards west is deflected toward north by a magnetic field. The direction of the
magnetic field is
(a) Upward
(b) downward
(c) towards south
(d)
towards east.
Answer
(d) towards east.
22.
The instrument that use to defect electric current in the
circuit is known as
(a) electric motor
(b) A.C generator
(c)
galvanometer
(d) none of the above
Answer
(a) electric motor
23.
A positive charge is moving upwards in a magnetic field
directed towards north. The particle will be deflected towards
(a) west
(b) north
(c) south
(d) east
Answer
(a) west
24.
At the time of short circuit, the current in the circuit
(a) vary continuously
(b) reduced considerably
(c) increases heavily
(d) does not change
Answer
(c) increases heavily
25.
The magnetic field near a long straight wire is described
by
(a) Straight field lines parallel to the wire.
(b) Straight field lines
perpendicular to the wire.
(c) Connective circle centered on the wire.
(d)
Radial field lines starting from the wire.
Answer
(c) Connective circle centered on the wire.
26.
By which instrument, the presence of magnetic field be
determined?
(a) Magnetic Needle
(b) Ammeter
(c) Galvanometer
(d)
Voltmeter
Answer
(d) Voltmeter
27.
Inside the magnet, the field lines moves
(a) from north to
south
(b) from south the north
(c) away from south pole
(d) away from
north pole
Answer
(a) from north to south
28.
Assertion: It is fatal to touch a live electric wire as the
person gets a severe electric shock. In some cases, electric shock can even kill
a person.
Reason: The electric current passes through the body to the earth
forming a circuit and bums the blood.
(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.
(e) Both A and R are false.
Answer
(a) Both A and R are true and R is the correct explanation of A.
29.
Assertion: Strength of an electromagnet depends on the
magnitude of current flowing through them.
Reason: Electromagnets are majorly
used for lifting heavy weights.
(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.
(e) Both A and R are false.
Answer
(b) Both A and R are true but R is not the correct explanation of A.
30.
Which device produces the electric current?
(a)
generator
(b) galvanometer
(c) ammeter
(d)
motor
Answer
(a) generator
31.
The essential difference between 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
commentator.
Answer
(d) A.C. generator has slip rings while the D.C. generator has commentator.
32.
Commercial electric motors do not use
(a) an electromagnet
to rotate the armature
(b) effectively large number of turns of conducting
wire in the current carrying coil
(c) a permanent magnet to rotate the
armature
(d) a soft iron core on which the coil is
wound
Answer
(c) a permanent magnet to rotate the armature
33.
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
34.
Which one 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
(d) The field consists of concentric circles centered on the wire.
35.
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
36.
The main advantage of A.C power transmission over D.C power
transmission over’ long distance is
(a) AC transmit without much loss of
energy
(b) less insulation problem
(c) less problem of instability
(d)
easy transformation.
Answer
(a) AC transmit without much loss of energy
37.
The rectangular coil of copper wires is rotated in a magnetic
field. The direction of induced current change once in each
(a) one
revolution
(b) one fourth revolution
(c) half revolution
(d) two
revolutions
Answer
(b) one fourth revolution
38.
The condition for the praenomen of electromagnetic induction
is that there must be a relative motion between
(a) the galvanometer and
magnet
(b) the coil of wire and galvanometer
(c) the coil of wire and
magnet
(d) the magnet and galvanometer
Answer
(c) the coil of wire and magnet
39.
Direction of rotation of a coil in electric motor is
determined by
(a) fleming’s right hand rule
(b) fleming’s left hand
rule
(c) faraday law of electromagnetic inductors
(d) None of
above
Answer
(b) fleming’s left hand rule
40.
Which of the following statement is not correct about the
magnetic field?
(a) Magnetic field lines form a continuous closed curve.
(b) Magnetic field line do not interest each other.
(c) Direction of tangent
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.
41.
A.C generator works on the principle of
(a) force
experience by a conductor in magnetic field
(b) electromagnetic induction
(c) electrostatic
Answer
(d) force experience by a charge particle in electric field.
42.
The most important safety device method used for protecting
electrical appliances from short circuiting or overloading is
(a)
Earthing
(b) use of stabilizer
(c) use of electric meter
(d)
fuse
Answer
(d) fuse
43.
Small current in a circuit is detected by
(a)
Galvanometer
(b) Solenoid
(c) Voltmeter
(d) Fleming’s left hand
rule
Answer
(a) Galvanometer
44.
Potential difference between a live wire and a neutral wire
is
(a) 200 volt
(b) 150 volt
(c) 210 volt
(d) 220
volt
Answer
(d) 220 volt
45.
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
above
Answer
(d) All of above
46.
Electric motor converts
(a) Mechanical energy into
electrical energy
(b) Mechanical energy into heat energy
(c) Electrical
energy into heat energy
(d) Electrical energy into mechanical
energy
Answer
(d) Electrical energy into mechanical energy
47.
Fleming’s left hand and Right hand rules are used in
(а)
Generator and electric motor
(b) Electric motor and generator
(c) any rule
can be used for any device
(d) both are not applied for generator and
motor.
Answer
(b) Electric motor and generator
48.
A current carrying conductor placed in magnetic field
experiences a force. The displacement of the conductor in magnetic field can be
increased by
(a)Decreasing the magnetic field.
(b) Decreasing the current
in the conductor.
(c) Increasing the magnetic field.
(d) None of the
above.
Answer
(c) Increasing the magnetic field.
49.
Which of the following properties of a proton can change when
it moves freely in a magnetic field
(a) mass
(b) speed
(c) velocity
(d) momentum
Answer
(c) velocity
50.
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
(a) in the direction opposite to the current
51.
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
52.
Magnetic Effect of Electric Current Class 10 MCQ Question 1.
Magnetic effect of current was discovered by
(a) Oersted
(b) Faraday
(c) Bohr
(d) Ampere
Answer
(a) Oersted
53.
A device for producing electric current is called a
(a)
Galvanometer
(b) Motor
(c) Generator
(d)Ammeter
Answer
(c) Generator
54.
For a current in a long straight solenoid, N- and S-poles are
created at the two ends. Among the following statements, the incorrect statement
is
(a) the field lines inside the solenoid are in the form of straight lines
which indicates that the magnetic field is the same at all points inside the
solenoid
(b) the strong magnetic field produced inside the solenoid can be
used to magnetise a piece of magnetic material like soft iron, when placed
inside the coil
(c) the pattern of the magnetic field associated with the
solenoid is different from the pattern of the magnetic field around a bar
magnet
(d) the N- and S-poles exchange position when the direction of current
through the solenoid is reversed.
Answer
Answer: (c) the pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet
55.
In the arrangement shown in the figure there are two coils
wound on a non-conducting cylindrical rod. Initially the key is not inserted.
Then the key is inserted and later removed. Then
(a) the deflection in the galvanometer remains zero throughout.
(b) there is
a momentary deflection in the galvanometer but it dies out shortly and there is
no effect when the keys is removed.
(c) there are momentary galvanometer
deflections that die out shortly; the deflections are in the same direction.
(d) there are momentary galvanometer deflections that die out shortly; the
deflection are in opposite directions.
Answer
Answer: (d) there are momentary galvanometer deflections that die out shortly; the deflection are in opposite directions.
56.
Choose the incorrect statement
(a) Fleming’s right-hand
rule is a simple rule to know the direction of induced current.
(b) The
right-hand thumb rule is used to find the direction of magnetic fields due to
current carrying conductors.
(c) The difference between the direct and
alternating currents is that the current always flows in one direction, whereas
the alternating current reverses its direction periodically.
(d) In India,
the AC changes direction after every \(\frac{1}{50}\)
second.
Answer
Answer: (d) In India, the AC changes direction after every \(\frac{1}{50}\) second.
57.
A constant current flows in a horizontal wire in the plane of
the paper from east to west as shown in the figure. The direction of magnetic
field at a point will be North to 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
Answer: (b) directly below the wire
58.
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
Answer: (c) same at all points
59.
The most important safety method used for protecting home
appliances from short circuiting or overloading is by
(a) earthing
(b) use
of fuse
(c) use of stabilizers
(d) use of electric
meter.
Answer
Answer: (b) use of fuse
60.
Select the incorrect statement
(а) Magnetic field lines
are closed curves
(b) No two field lines can cross each other
(c) Field
lines can cross each other
(d) The relative strength of the magnetic field is
shown by degree of closness of the field lines.
Answer
Answer: (c) Field lines can cross each other
61.
Magnetic field lines around a straight conductor forms a
pattern of
(a) concentric circles
(b) concentric ellipse
(c) straight
line
(d) square shape.
Answer
Answer: (a) concentric circles
62.
Electric motor is a device which converts
(a) mechanical
energy to electrical energy
(b) electrical energy to mechanical energy
(c)
chemical energy to mechanical energy
(d) mechanical energy to light
energy.
Answer
Answer: (b) electrical energy to mechanical energy
63.
The direction of induced current is given by
(a) Fleming’s
right hand rule
(b) Fleming’s left hand rule
(c) Right hand thumb rule
(d) Left hand thumb rule.
Answer
Answer: (a) Fleming’s right hand rule
64.
The insulation colour of earth wire is
(a) blue
(b)
red
(c) green
(d) white.
Answer
Answer: (c) green
65.
In India the potential difference between live wire and
neutral wire is
(a) 240 V
(b) 250 V
(c) 280 V
(d) 220
V.
Answer
Answer: (d) 220 V.