Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
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
संबंधित प्रश्न
S.I. unit and commercial unit of electrical energy are same.
All electrical appliances in a household circuit work at the same voltage.
One kilowatt hour is equal to ............ joule.
From where does the electricity come to our home ?
For which unit do we pay our electricity bill?
If an appliance of power P watt is used for time t hour. How much electrical energy is consumed in kWh?
An electric iron of power 1.5 kW is used for 30 minutes to press the clothes. Calculate the electrical energy consumed in
- kilowatt-hour
- joule.
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.
State and define the household unit of electricity.
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.
