Advertisements
Advertisements
प्रश्न
A coil of copper wire is connected to a galvanometer. What would happen if a bar magnet is:
(i) Pushed into the coil with its north pole entering first?
(ii) Held at rest inside the coil?
(iii) Pulled out again?
Advertisements
उत्तर
(i)
When the north-pole is pushed into the coil, a momentary deflection is observed in the galvanometer that indicates the production of a momentary current in the coil.
(ii)
When the magnet is held at rest, there is no deflection in the galvanometer, indicating that no current is produced in the coil.
(iii)
When the north-pole is pulled out from the coil, the deflection of the galvanometer is along the opposite direction, indicating the production of an opposite current.
APPEARS IN
संबंधित प्रश्न
Name the quantity whose unit is kilowatt?
Two bulbs are rated 60 W, 220 V and 60 W, 110 V respectively. Calculate the ratio of their
resistances
The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.

(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.
Define electric power. An electrical device of resistance R is connected across a source of voltage V and draws a current I. Derive an expression for power in terms of current and resistance.
What changes in energy occur in an electric heater?
What is ‘Rating’ of an electric appliance?
Why is the electric power from the generating station transmitted at high voltage?
State (i) the S. I. unit, (ii) the household unit, of electrical energy. How are these units related?
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the resistance of its filament while glowing.
An Electric bulb is marked 100 W, 230 V. What how long would this lamp take to consume one unit of electricity?
