Advertisements
Advertisements
Question
Two lamps, one rated 220 V, 50 W and the other rated 220 V, 100 W, are connected in series with mains of 220 V. Explain why does the 50 W lamp consume more power.
Solution
Resistance of 220 V , 50 W lamp is
`"R"_1 = "V"^2/"P"_1 = 220^2/50 = 968 Omega`
Resistance of 220 V , 100 W lamp is
`"R"_2 = "V"^2/"P"_2 = 220^2/100 = 484 Omega`
since the two lamps are connected in series
so same current I passes through each lamp.
Power consumed in 220 V , 50 W lamp is P1 = I2R1
Power consumed in 220 V , 100 W lamp is P2 = I2R2
Since `"R"_1 > "R"_2 , "P"_1 > "P"_2`.
i.e. 50 W lamp consumes more power.
APPEARS IN
RELATED QUESTIONS
S.I. unit and commercial unit of electrical energy are same.
The unit in which we pay the cost of electricity is ..........
One kilowatt hour is equal to ............ joule.
If out of the two lighted bulbs in a room, one bulb suddenly fuses, then
From where does the electricity come to our home ?
For which unit do we pay our electricity bill?
What is an electric fuse? State its purpose in the household electrical circuit.
In a premise 5 bulbs each of 100 W, 2 fans each of 60 W, 2 A.Cs each of 1.5 kW is used for 5 h per day. Find:
- Total power consumed per day,
- Total power consumed in 30 days,
- Total electrical energy consumed in 30 days.
- The cost of electricity at the rate of ₹ 6.25 per unit.
What is the voltage of the electricity that is generally supplied to a house?
What is the resistance, under normal working conditions, of an electric lamp rated at '240 v, 60 W' ? If two such lamps are connected in series across a 240 V mains supply, explain why each one appears less bright.
