Advertisements
Advertisements
Question
Why is heating coil wound in the form of a helix in electric stove?
Advertisements
Solution
This reduces the area over which element of heater is spread. As heat is produced over smaller area, therefore temperature of its element rises to about 1000°C.
RELATED QUESTIONS
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?
How many joules are there in one kilowatt-hour?
Two lamps, one rated 220 V, 50 W and the other rated 220 V, 100 W, are connected in serieswith mains of 220 V. Explain why does the 50 W lamp consume more power
What is wrong with the circuit diagram (Fig. 34)? Carefully check the symbols and assign proper positive and negative signs to them.

Why is a concave reflector placed behind the heating element in a room heater.
Two electric lamps each rating 100 W, 110 V are connected in series to a 220 V power supply and two other electric lamps each of marking 100 W, 220 V are connected in parallel to the same power supply. Will anyone of the two combinations give more light than the other? Give a reason for your answer.
How can electric energy consumed by an electric appliance be calculated in kilowatt hour (kWh)?
Establish the relation that heat produced in a metallic conductor due to the flow of current is V2t/R joules, where V is the potential difference across the ends of the conductor, R its resistance and t is the time in second for which current flows.
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the resistance of its filament while glowing.
What is the meaning of electric power of an electrical device? Write its SI unit.
