Advertisements
Advertisements
प्रश्न
Name two common material used for heating elements.
Advertisements
उत्तर
Nichrome and manganin are the common alloys that are mostly used for making heating elements.
Nichrome is: 60% nickel + 25% iron + 15% chromium.
Manganin is: 83% manganese + 13% copper + 4% nickel.
संबंधित प्रश्न
An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be ______.
The commercial unit of energy is :
(a) watt
(b) watt-hour
(c) kilowatt-hour
(d) kilo-joule
At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulb could be switched on in the house at the same time (if they are all connected in parallel)?
In an electric radiator or room heater, state with reason, why the porcelain tube wound with a nichrome wire is placed between the pole and principal focus of the parabolic concave reflector.
An electric bulb is marked 100 W, 230 V. What does this mean?
A battery of e.m.f. 12V and internal resistance 1.6 Ω is connected to two resistors of 4Ω and 6Ω connected in parallel. Calculate:
(i) the current drawn from the battery,
(ii) the power dissipated in each resistor,
(ii)the total power supplied by the battery.
A bulb is marked 100W, 220V and an electric heater is marked 2000 W, 220 V.
(i) What is the ratio between the resistances of these two devices?
(ii) How does the power-voltage rating of a device help us to decide about the type of leads (connecting wires) to be used for it?
(iii) In which of the above two devices, a thicker connecting wire of lead is required?
Find the cost of operating an electric toaster for two hours if it draws 8 A current on a 110 volt circuit. The cost of electrical energy is Rs. 2.50 per kWh.
