Advertisements
Advertisements
Question
Electrical power p is given by the expression P = (Q × V) ÷ time. Express the power P in terms of current and resistance explaining the meaning of symbols used there in.
Advertisements
Solution
Electrical Power, P = `I^2R`. Where I is current and R is resistance.
APPEARS IN
RELATED QUESTIONS
At what frequency is AC supplied to residential houses?
Name the quantity whose unit is kilowatt?
An electric heater is rated at 2 kW. Electrical energy costs Rs 4 per kWh. What is the cost of using the heater for 3 hours?
(a) Rs 12
(b) Rs 24
(c) Rs 36
(d) Rs 48
The SI unit of energy is :
(a) joule
(b) coulomb
(c) watt
(d) ohm-metre
A bulb marked 12 V, 24 W operated on a 12 volt battery for 20 minutes. Calculate:
(i) the current flowing through it, and
(ii) the energy consumed
A resistor of resistance R is connected to an ideal battery. If the value of R is decreased, the power dissipated in the resistor will ______________ .
State (i) the S. I. unit, (ii) the household unit, of electrical energy. How are these units related?
A battery of e.m.f. 12V and internal resistance 1.6 Ω is connected to two resistors of 4Ω and 6Ω connected in parallel. Calculate:
(i) the current drawn from the battery,
(ii) the power dissipated in each resistor,
(ii)the total power supplied by the battery.
The resistance of filament of an electric heater is 500 Ω It is operated at 200V for 1 hour daily. Calculate the current drawn by the heater and the energy consumed in joule.
1 mV is equal to:
