Advertisements
Advertisements
प्रश्न
State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
Advertisements
उत्तर
The heating element is between the pole and principal focus of concave reflector. This in turn, gives rise to a divergent beam of heat radiations.
संबंधित प्रश्न
List the names of three electrical gadgets used in your house. Write their power, voltage ratingand approximate time for which each one is used in a day. Hence find the electrical energyconsumed by each in a day.
An electric bulb is rated at 220 V, 100 W. (a) what is its resistance? (b) what safe current can be passed through it?
State the reason why, in a three pin plug, the earth pin is longer and thicker than the other two.
A bulb is connected to a battery of e.m.f. 6V and internal resistance 2Ω A steady current of 0.5A flows through the bulb. Calculate the resistance of the bulb.
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?
A 100-watt electric bulb is used for 5 hours daily and four 60 watt bulbs are used for 5 hours daily. Calculate the energy consumed (in kWh) in the month of January.
If a heater coil rated lkW, 220 V is connected in series with an electric bulb of 100 W, 220 V and are supplied 200V, power consumed by the bulb in this circuit is ______.
A electric bulb is rate 220 V, 60 W. its electric cell resistance is nearly
Using a long extension cord in which each conductor has a resistance of 8Ω, a bulb marked as '100 W, 200 V' is connected to a 220 V dc supply of negligible internal resistance as shown in the figure. The power delivered to the bulb is ______ W.
