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प्रश्न
विकल्प
increases
decreases
remains the same
- increases or decreases
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उत्तर
When the resistance of a conductor increases, the current decreases.
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संबंधित प्रश्न
When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.
Will the compass needle show deflection when the switch in the circuit shown by figure is closed?
An electromagnet does not attract a piece of iron.
Name the scientist who discovered the magnetic effect of current.
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?
Name one device which works on the magnetic effect of current.
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.
(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
Draw magnetic field lines produced around a straight current carrying conductor passing through a cardboard. How will the strength of the magnetic field change when the point where magnetic field is to be determined is moved away from the conductor?
Name any two appliances which works on the phenomenon of magnetic effect of electric current.
If the key in the given arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are ____________.
Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?
What are MCBs? How do they work?
Sailors use ______ to find direction in order to navigate on the sea.
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?
Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.
