Advertisements
Advertisements
Question
Why is heating element wound on a long porcelain rod in a room heater.
Solution
This reduces the area over which element of the heater is spread. As heat is produced over smaller area, therefore temperature of its element rises to about 1000°C.
APPEARS IN
RELATED QUESTIONS
An electric bulb is rated ‘100 W, 250 V’. How much current will the bulb draw if connected to a 250 V supply?
Why does not the heating coil produce any visible light? in an electric stove.
What is ‘Rating’ of an electric appliance?
An electric bulb is rated 240V-60W and is working at 100% efficiency.
(i) Calculate the resistance of bulb.
(ii) (a) Draw the circuit diagram.
(b) What is the rate of conversion of energy in each bulb?
(c) Total power used by the bulbs.
1 mV is equal to:
A room has AC run for 5 hours a day at a voltage of 220V. The wiring of the room consists of Cu of 1 mm radius and a length of 10 m. Power consumption per day is 10 commercial units. What fraction of it goes in the joule heating in wires? What would happen if the wiring is made of aluminium of the same dimensions?
`[ρ_(Cu) = 1.7 xx 10_(Ωm)^-8, ρ_(Al) = 2.7 xx 10^-8 Ωm]`
