Advertisements
Advertisements
Question
An electric kettle is rated 3kW, 250V. What should be the current capacity of the fuse with it?
Advertisements
Solution
The maximum current capacity of kettle, I = `"P"/"V" = 3000/250 = 12"A"`
Thus, the fuse should be of current capacity slightly less than 12A.
RELATED QUESTIONS
1 kWh = ________ J
An electric fan runs from the 230 V mains. The current flowing through it is 0.4 A. At what rate is electrical energy transferred by the fan?
Explain why, filament type electric bulbs are not power efficient.
A bulb marked 12 V, 24 W operated on a 12 volt battery for 20 minutes. Calculate:
(i) the current flowing through it, and
(ii) the energy consumed
Two resistors A and B of resistance 4 Ω and 6 Ω respectively are connected in parallel. The combination is connected across a 6 volt battery of negligible resistance. Calculate: (i) the power supplied by the battery, (ii) the power dissipated in each resistor.
Fig . shows the essent ial features of a battery operated bell. The hammer strikes the gong when the swi tch is closed . State and explain the effect of using the following material successively to form the core.
(a) Plastic
(b) Steel
(c) Copper
Why is heating element wound on a long porcelain rod in a room heater.
What is ‘Rating’ of an electric appliance?
At what voltage is the electric power generated at the generating station? Explain the transmission of this power to your house.
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]`
