Advertisements
Advertisements
प्रश्न
Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:
(a) the current is passed through the wire.
(b) the current through the wire is increased
(c) the current through the wire is reversed.
Advertisements
उत्तर
- When a current is passed through the wire, the magnetic needle gets deflected.
- When the current through the wire is increased, the deflection of the magnetic needle increases.
- When the current through the wire is reversed, the magnetic needle is deflected in the opposite direction.
APPEARS IN
संबंधित प्रश्न
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
An electromagnet does not attract a piece of iron.
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
Name the scientist who discovered the magnetic effect of current.
Describe some experiment to show that the magnetic field is associated with an electric current.
If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be:
(a) west pole
(b) south pole
(c) north pole
(d) east pole
For the coil in the diagram below, when the switch is pressed:
(a) what is the polarity of end A?
(b) which way will the compass point then?

Which way does the wire in the diagram below tend to move?
Write the correct option by observing the figures.

(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
Explain the magnetic field created around a straight current carrying conductor with the help of a diagram.
What is that instrument which can detect the presence of electric current in a circuit?
Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel at the night to get dim light. Has she taken the right step? Give one reason to justify your answer.
Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason.
Define the magnetic effect of electric current.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:

- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
Using an electromagnet, you can make a working model of a railway signal as shown in figure.

