Advertisements
Advertisements
प्रश्न
When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.
If S is kept closed, will the pointer:
(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened
Advertisements
उत्तर
return to zero
After some time, the magnetic field gets constant; this means that there is no relative change in the value of magnetic field. Therefore, the circuit will have zero induced current.
APPEARS IN
संबंधित प्रश्न
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
Name the scientist who discovered the magnetic effect of current.
Fill in the following blank with suitable words:
The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.
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
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the magnet is a rest in the coil?
How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?
(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
(ii) Global warming is a desirable aspect of the intensified greenhouse effect.
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.
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.
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.
How does the magnetic effect of electric current help in the working of an electric bell? Explain with the help of a diagram.
______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.
An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.
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?
