Magnetic Effects of Electric Current

Q. The shape of the magnetic field lines is of around a straight current carrying conductor.

1. straight lines
2. concentric circles
3. a triangle
4. sphere

Q.

Question 7
Will the compass needle show deflection when the switch in the circuit shown in the figure is closed?

Q.

Question 1

When an electric current flows through a copper wire AB as shown in Figure, the wire

(a) Deflects a magnetic needle placed near it

(b) Becomes red hot

(c) Gives electric shock

(d) Behaves like a fuse

Q. What is the magnetic effect of electric current?

Q.

The magnetic effect of electric current was first observed by:

1. W.H. Whitkar

2. H.C. Oersted

3. Isaac Newton

4. Galileo Galilei

Q. A circular loop of flexible conducting material is kept in a magnetic field directed perpendicularly into the plane . By holding the loop at diametrically opposite points it is stretched outwards then in which direction current is induced in the coil?

Q.

Question 17

Your teacher has shown you the following activity

Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the Figure 14.3. The current is switched on and some pins are placed near the ends of the nail.

Write down any three questions that come to your mind about this activity

Q.

The field at the centre of a long circular coil carrying current will be parallel straight lines.

1. True
2. False

Q. The magnetic field at a distance of 2cm from the axis of a straight conducter carrying current is 12mT. The current in a con ducter in ampere is

Q.

The magnetic field lines form closed loops.

State True or False.

1. True

2. False

Q.

On which of the following factors does the direction of deflection of a magnetic needle depend?

1. Direction of current flowing through the circuit

2. Size of Magnetic Needle

3. Magnitude of current flowing through the circuit

4. Both A and B

Q.

On which of the following factor, the direction of deflection of a magnetic needle of a compass depends when the compass is kept near a current carrying wire?

1. Direction of current flowing through the circuit

2. Magnitude of current flowing through the circuit

3. Both A and B

4. Size of Magnetic Needle

Q.

Question 7
Will the compass needle show deflection when the switch in the circuit shown in the figure is closed?

Q.

When we bring a magnetic needle near a current carrying conductor, it gets deflected. This deflection is an example of:

1. Chemical effect of electric current

2. Heating effect of electric current

3. Magnetic effect of electric current

4. None of these

Q.

_________is the pattern of magnetic field around a straight current carrying conductor.

1. Parallel lines

2. Concentric helix

3. Concentric circles

4. Concentric spiral

Q.

Question 6
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.

Q.

The magnetic effect was first observed by a scientist Hans Christian Oersted

1. True
2. False

Q. Match the following based on the effects of current.

1. Heating effect
2. Magnetic effect
3. Current
4. Electromagnet

Q.

When we bring a magnetic needle near a current carrying conductor, it gets deflected. This deflection is an example of:

1. Chemical effect of electric current

2. Heating effect of electric current

3. Magnetic effect of electric current

4. Electro-optic effect of electric current

Q.

Select the correct option:

I) A magnetic needle responds to the Earth’s magnetic field.

II) A magnetic needle gets deflected when a magnet is brought near it.

III) A magnetic needle is made up of a non-magnetic material.

1. I and III are correct

2. only I is correct

3. only II is correct

4. I and II are correct

Q.

The device used to protect electric circuit is ____________(fuse /battery ).

Q. Why the magnetic field produced by a straight current carrying conductor is in the shape of concentric circles?

Q. Choose the device that works on the principle of magnetic effects of electric current.

1. Iron box
2. Wind turbine
3. Lever
4. Loudspeakers

Q.

Why is a magnetic needle used in the tester made to test mostly weak conductors? [3 MARKS]

Q. A metalic ring is attached with the wall of a room. When the north pole of a magnet is brought near to it the induced current in the induced current in the ring will be (a) first clock wise then anticlockwise (b) in clock wise direction (c) in anticlockwise direction (d) first clock wise then close wise

Q.

Give reason when electricity passes through a wire, it deflects the compass needle.

Q. Match the following based on the effects of current.

1. Heating effect
2. Magnetic effect
3. Current
4. Electromagnet

Q.

When we bring a magnetic needle near a current carrying conductor it gets deflected. This deflection is an example of:

1. Heating effect of electric current

2. Magnetic effect of electric current

3. None of these

4. Chemical effect of electric current

Q. A wire shaped to a regular hexagon of Side 2 centimetre carries a current of 2 ampere find the magnitude of magneticfield at the centre of hexagon

Q.

When two magnets are placed closed to each other, north pole of one magnet gets attracted to the south pole of the other magnet.

1. True

2. False