CBSE X Science Magnetic Effects of Current - EducareHut (Next Gen Knowledge Point)

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#1. 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

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

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

The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet

The N and S-poles exchange position when the direction of current through the solenoid is reversed

Explanation: Option (a), (b) and (d) are correct. Only option (c) is incorrect because the pattern of magnetic fields due to solenoid and bar magnet is almost same.

#2. A positive charge is moving upwards in a magnetic field directed towards north. The particle will be deflected towards

west

north

south

east

Explanation: (a) Apply fleming’s left hand rule

#3. Which of the following statement is not correct about the magnetic field?

Magnetic field lines form a continuous closed curve.

Magnetic field line do not interest each other.

Direction of tangent at any point on the magnetic field line curve gives the direction of magnetic field at that point.

Outside the magnet, magnetic field lines go from South to North pole of the magnet.

Explanation:
(d) Outside the magnet, magnetic field line emerges from North-pole and moves towards south-pole.

#4. Which device produces the electric current?

generator

galvanometer

ammeter

motor

#5. For a current in a long straight solenoid N-pole and S-pole are created at the two ends. Among the following statements, the incorrect statement is

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.

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.

The pattern of the magnetic field associated with the solenoid is different from the pattern of the magnetic field around a bar magnet.

The N-pole and S-pole exchange position when the direction of current through the solenoid is reversed.

Explanation: A solenoid behaves like a bar magnet. Hence the pattern of magnetic field associated with solenoid and around the bar magnet is same.

#6. Which of the following diagrams correctly shows the magnetic field produced by a current- carrying wire?

#7. Fleming’s left hand and Right hand rules are used in

Generator and electric motor

Electric motor and generator

any rule can be used for any device

both are not applied for generator and motor.

Explanation: Electric motor employs Fleming left hand rule while for generator, Fleming right-hand rule is used.

#8. The factors on which one magnetic field strength produced by current carrying solenoids depends are

Magnitude of current

Number of turns

Nature of core material

All of the other 3 answers

Explanation: (d) Factors shown in (a), (b) and (c).

#9. The best material to make permanent magnets is

aluminium

soft iron

copper

alnico

#10. The direction of induced current is given by

Fleming’s right hand rule.

Fleming’s left hand rule.

Right hand thumb rule.

Left hand thumb rule.

#11. The shape of the magnetic field lines produced by a current carrying conductor are:

Straight lines

Concentric circles

Concentric ellipse

Concentric parabolas

#12. The pattern of the magnetic field produced by the straight current carrying conducting wire is

in the direction opposite to the current

in the direction parallel to the wire

circular around the wire

in the same direction of current

Explanation:(c) Magnetic field line around a current carrying straight conductor is represented by concentric circles.

#13. A soft iron bar is introduced inside the current carrying solenoid. The magnetic field inside the solenoid

will decrease

will remains same

will increase

will become zero

Explanation: (c) Soft iron inside the current carrying solenoid act as an electromagnet.

#14. An electric generator actually acts as

a source of electric charge.

a source of heat energy.

an electromagnet.

a converter of energy.

#15. 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 to south.

Directly above the wire

Directly below the wire

At a point located in the plane of the paper on the north side of the wire

At a point located in the plane of the paper on the south side of the wire

Explanation: If we observe the direction of magnetic field by applying right hand thumb rule then, we will find that the direction of magnetic field is from North to South below the wire.

#16. A.C generator works on the principle of

force experience by a conductor in magnetic field

electromagnetic induction

electrostatic

force experience by a charge particle in electric field.

Explanation: Generator works on principle of electromagnetic induction.

#17. . A current flows in a wire running between the S and N poles of a magnet lying horizontally as shown in the figure .The force on the wire due to the magnet is directed:

From N to S

From S to N

Vertically downwards

Vertically upwards

#18. Inside the magnet, the field lines moves

from north to south

from south the north

away from south pole

away from north pole

Explanation:
(a) Magnetic field inside the magnet moves from south to north pole.

#19. An electric motor is a device which transforms

Mechanical energy into electrical energy

Electrical energy into mechanical energy

Kinetic energy into potential energy

Electrical energy into Potential energy

#20. We can induce the current in a coil by

moving the coil in a magnetic field

by changing the magnetic field around it

by changing the orientation of the coil in the magnetic field

All of above

#21. The device used for producing electric current is called a

Generator.

Galvanometer.

Ammeter.

Motor.

#22. 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

carbon brush

commutator

slip ring

armature

Explanation: (b) A device that reverses the direction of current in the arms of armature through a circuit is called commutation.

#23. Material of the core of a strong magnet is

aluminum

soft iron

copper

steel

#24. A current carrying conductor is held in exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should be passed in the conductor:

From top to bottom

From left to right

From bottom to top

From right to left

#25. Who has stated the Right hand Thumb Rule?

Orsted

Fleming

Einstein

Maxwell

Finish