Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
(i) From P = `"V"^2/"R"`
Resistance of bulb (R) = `"V"^2/"P" = (240 xx 240)/60 = 960 Omega`
(ii) (a)
(b) Resistance of bulbs in series = (960 + 960) Ω = 1920 Ω
∴ Current in series circuit I = `"V"/"R" = 240/1920 = 0.125` A
∴ Rate of conversion of energy in any one bulb in 1 second = I2Rt
= (0.125)2 × 960 × 1 = 15.5
(c) Power of 1 bulb in series circuit = 15 W
So poewr of 2 bulb in series circuit = 2 × 15 W = 30 W.
APPEARS IN
संबंधित प्रश्न
Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?
What is the meaning of the symbol kWh? Which quantity does it represent?
Explain why, filament type electric bulbs are not power efficient.
Name the physical quality which is measured in
(i) Kw (ii) kWh
The diagram 31 shows a 3 terminal plug socket.
(i) What is the purpose of the terminal E?
(ii) To which part of the appliance is the terminal E connected?
(iii) To which wire L or N, is the fuse connected and why?
‘The current rating of a fuse is 5A’. Comment on this statement.
An electric heater is rated 220 V, 550 W. Calculate the electrical energy consumed in 3 hours?
An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the resistance of its filament while glowing.
What is the commercial unit of electrical energy? Represent it in terms of joules.
A conductor of 10 Ω is connected across a 6 V ideal source. The power supplied by the source to the conductor is ______.
