Important Questions for Class 10 Science Chapter 13 – Magnetic Effects Of Electric Current
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# Important Questions for Class 10 Science Chapter 13 – Magnetic Effects Of Electric Current

Important questions for class 10 science chapter 13 – Magnetic Effects of Electric Current cover essential topics from the chapter. There are small magnets embedded in the compass needles. A pole that points north is called a north pole, and one that points south is called a south pole. Magnets have a strong magnetic field surrounding them that can be used to detect their force. Field lines represent the path along which a hypothetical free north pole would travel. The magnetic field tends to converge in areas where they are stronger. Based on the right-hand rule, the line segments revolve around the wire in a circular pattern.

While solving important questions for class 10 science chapter 13 – Magnetic Effects of Electric Current, students are required to pay attention dealing with the following topics:

• Field lines and magnetic field
• The right-hand thumb rule
• Current flowing through a circular loop produces a magnetic field
• A solenoid’s magnetic field is caused by current flowing through it
• Inductions by electromagnetic forces
• The left-hand rule of fleming.

Below are some of the important questions for class 10 science chapter 13 – Magnetic Effects of Electric Current from an examination point of view.

## Class 10 Science Important Questions Chapter 13 – Magnetic Effects of Electric Current

Q1. What is an electromagnet? Write two uses of an electromagnet?

Solution:

They are the type of magnet in which the magnetic field is produced by an electric current i.e. when current is passed through a solenoid it behaves as a magnet and is called an electromagnet.

The two uses of an electromagnet are-

1. Used in electrical devices like motors, generators etc.
2. Used to lift heavy iron pieces.

Q2. Which sources produce alternating current?

Solution:

The sources that produce alternating current are-

• House generators
• Car alternators
• Bicycle dynamos
• Hydroelectric Power Plants
• Thermal power generators
• Nuclear power generators,
• AC generators etc.

Q3. What is the function of an earth wire? Why is it necessary to earth metallic casing of electric appliances?

Solution:

The earth wire is used for the safety measures that have green insulation and is connected to a metal plate deep in the earth near our houses.  Appliances like the electric press, toaster, table fan, refrigerator, etc have the metallic body that needs to connect to the earth wire this will provide a low resistance path for the. Thus, if any leakage of current occurs to the metallic body of the appliance it keeps potential to that of the earth, and this may prevent the severe electric shock.

Q4. List the properties of magnetic lines of force.

Solution:

Properties of magnetic field lines of force are as follows:

1. Outside a magnet, the field lines are directed from the N-pole of the magnet towards the S-pole, and inside the magnet, lines are directed from S-pole to N-pole.
2. Magnetic field lines are closed curves.
3. No two magnetic field lines intersect each other.
4. The density of magnetic lines decreases, when the distance between the poles increases.

Q5. What is the principle of an electric motor?

Solution:

Electric motor is a rotating device that can convert electrical energy into mechanical energy.  An electric motor is based on the principle that the current-carrying conductor experiences a force when placed in a magnetic field. The direction of the force is given by Fleming’s left-hand rule, if the direction of the magnetic field and that of the current are mutually perpendicular.

Q6. How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.

Solution:

The solenoid has a soft iron core with insulated copper wire over it so it can behave like a magnet. A strong and uniform magnetic field is produced around the solenoid when a current is passed through it. which is similar to that of the magnetic field of a bar magnet.

Solenoid behaves like a strong bar magnet. We can determine the poles of magnets formed by solenoids. The solenoid repels if the north pole of a bar magnet is brought near the negative terminal of the battery, the same for the south pole. As we know, poles repel each other.

Q7. Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.

Solution:

Yes, If the current in coil A is changed, then some current will be induced in coil B.

As the two circular coils, A and B are placed close to each other. When the current in coil A is changed, the magnetic field associated with it also changes. As coil B is placed near coil A, the magnetic field lines around coil B also change. Due to changes in magnetic field lines associated with coil B, a current is induced in coil B.

Q8. Give reason for the following

(i) There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid.

(ii) The current carrying solenoid when suspended freely rests along a particular direction.

Solution:

(i) There is either a convergence or a divergence of magnetic field lines near the ends of a current carrying straight solenoid because it behaves similar to that of a bar magnet and has a magnetic field line pattern similar to that of a bar magnet. Thus the ends of the straight solenoid behaves like poles of the magnet, where the converging end is the south pole and the diverging end is the north pole.

(ii) The current carrying solenoid behaves similar to that of a bar magnet and when freely suspended aligns itself in the north-south direction.

Q9. (a) State Right Hand Thumb rule to find the direction of the magnetic field around a current carrying straight conductor.

(b) How will the magnetic field be affected on:

(i) increasing the current through the conductor

(ii) reversing the direction of flow of current in the conductor?

Solution:

(a) It states that you are holding a current carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your finger will wrap around the conductor in the direction of the field lines of the magnetic field.

(b) (i) If the current is increased, the magnetic field strength also increases.

(ii) If the direction of current is reversed, the direction of magnetic field also get reversed.

Q10. State whether an alpha particle will experience any force in a magnetic field if (alpha particles are positively charged particles)

(i) it is placed in the field at rest.

(ii) it moves in the magnetic field parallel to field lines.

(iii) it moves in the magnetic field perpendicular to field lines.