Draw the pattern of magnetic field lines produced around a current carrying straight conductor passing perpendicularly through a horizontal cardboard. State and apply right-hand thumb rule to mark the direction of the field lines. How will the strength of the magnetic field change when the point where magnetic field is to be determined is moved away from the straight conductor? Give reason to justify your answer.

According to Maxwell's right-hand thumb rule, when you hold a current-carrying conductor in your right hand in such a way that your thumb points in the direction of the current then the direction in which your fingers encircle the conductor will give the direction of the magnetic field around it. Hence, if we hold the current-carrying straight wire in our right-hand so that thumb points in the direction of the current i.e in upward direction, the magnetic field lines will be in the anticlockwise direction. The density of magnetic lines of forces decreases as we move away from the straight conductor. This means that the separation between two magnetic lines of force increases when we move away from the straight conductor. Thus, we can say that the strength of the magnetic field and the distance of the point of observation from the wire are inversely proportional to each other. Hence, as we move away from the wire the strength of the magnetic field decreases.

List two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed.

The two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed are: By increasing the amount of current flowing in the solenoid, the strength of an electromagnet can be increased. By increasing the number of turns in the solenoid, the strength of an electromagnet can be increased.

State Fleming's left hand rule.

According to this rule, stretch the thumb, forefinger and middle finger of your left hand such that they are mutually perpendicular. If the first finger points in the direction of the magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

Explain the function of the following parts of an electric motor. Split ring

The split ring is mounted on the shaft of the coil in such a way that they also rotate when the coil rotates. The function of the split ring is to reverse the direction of current flowing through the coil every time the coil passes the vertical position during a revolution.

Explain the function of the following parts of an electric motor. Brushes

Carbon brushes are two flexible metal plates or carbon rods that are fixed to the base of the motor and are pressed lightly against the split rings so that they are constantly in touch with these. They also conduct current between stationary wires and moving parts, especially in a rotating shaft.

State the purpose of soft iron core used in making an electromagnet.

Electromagnets have a soft iron core because they easily magnetize or demagnetize when current flows or does not flow along the solenoid. Because the soft iron inside the coil becomes a magnet when the current flows, it strengthens the magnetic field.

Draw a labelled diagram to show how an electromagnet is made.

An electromagnet consists of a coil wound around an iron piece and connected to a battery. A current flowing through the wire produces a magnetic field that is focused in the hole, which serves as the coil's centre.

The change in magnetic field lines in a coil is the cause of induced electric current in it. Name the underlying phenomenon.

The phenomenon of electromagnetic induction is the production of induced current in a coil placed in a region where the magnetic field changes with time. The magnetic field may change due to a relative motion between the coil and a magnet placed near to the coil. The direction of the induced current is given by the Fleming's right-hand rule.

MEDIUM

10th CBSE

IMPORTANT

Earn 100

"Magnetic field is a physical quantity that has both direction and magnitude." How can this statement be proved with the help of magnetic field lines of a bar magnet?

Important Questions on Magnetic Effects of Electric Current

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2022 (Outside Delhi Term II - I)>Q 22

A student wants to use an electric heater, an electric bulb and an electric fan simultaneously. How should these gadgets be connected with the mains? Justify your answer giving three reasons.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2022 (Outside Delhi Term II - I)>Q 23

What is an electric fuse? How is it connected in a circuit?

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2022 (Outside Delhi Term II - I)>Q 25

What is electromagnetic induction? What is observed in the galvanometer when a strong bar magnet is held stationary near one end of a coil of large number of turns? Justify your answer.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2022 (Outside Delhi Term II - II)>Q 26

AB is a coil of copper wire having a large number of turns. The ends of the coil are connected with a galvanometer as shown.

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When the north pole of a strong bar magnet is moved towards the end B of the coil, a deflection is observed in the galvanometer. A deflection in the galvanometer is also observed when the magnet is held stationary and the coil moved towards the south pole of the magnet. Why?

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2022 (Outside Delhi Term II - III)>Q 27

AB is a coil of copper wire having a large number of turns. The ends of the coil are connected with a galvanometer as shown. When the north pole of a strong bar magnet is moved towards the end B of the coil, a deflection is observed in the galvanometer.

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What is a galvanometer? Why does its needle deflects when magnet is moved towards the coil to which it is connected?

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2023 (Delhi - I)>Q 28

Why should an ammeter have a low resistance?

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2023 (Delhi - I)>Q 29

The correct pattern of magnetic field lines of the field produced by a current carrying circular loop is:

HARD

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 13 - Magnetic Effects of Electric Current>CBSE-2023 (Delhi - I)>Q 30

An alpha particle enters a uniform magnetic field as shown. The direction of force experienced by the alpha particle is:

Question Image

"Magnetic field is a physical quantity that has both direction and magnitude." How can this statement be proved with the help of magnetic field lines of a bar magnet?

Important Questions on Magnetic Effects of Electric Current

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