Advertisements
Advertisements
Question
Write the formula for electric power in terms of potential difference and current.
Advertisements
Solution 1
In terms of potential difference and current, electric power is given as:
Electric power, P = potential difference, V x current, I
P = VI
Solution 2
In terms of potential difference and current, electric power is given as:
Electric power, P = potential difference, V x current, I
P = VI
RELATED QUESTIONS
Which of the following terms does not represent electrical power in a circuit?
At what frequency is AC supplied to residential houses?
Electrical power P is given by the expression P = (Q × V) ÷ time. What do the symbols Q and V represent?
An electric iron is rated at 750 W, 230 V. Calculate the electrical energy consumed by the iron in 16 hours .
An electrical appliance having a resistance of 200Ω is operated at 200 V. Calculate the energy consumed by the appliance in 5 minutes (i) in joules (ii) in kWh.
A servo voltage stabiliser restricts the voltage output to 220 V ± 1%. If an electric bulb rated at 220 V, 100 W is connected to it, what will be the minimum and maximum power consumed by it?
Fig . shows the essent ial features of a battery operated bell. The hammer strikes the gong when the swi tch is closed . State and explain the effect of using the following material successively to form the core.
(a) Plastic
(b) Steel
(c) Copper
Household wiring for lamp connections can either be done in parallel or in series.Which one would you prefer? Give a reason for your answer.
What do you understand by ‘earthing’? What are the advantages of earthing in a household electric circuit? Explain, how it is done?
At what voltage is the electric power generated at the generating station? Explain the transmission of this power to your house.
An Electric bulb is marked 100 W, 230 V. What current does it take?
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 total energy supplied by the battery in 10 minutes.
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.
An immersion rod having resistance of 50 Ω is connected to 220V main supply. Assuming that all the energy generated goes to heat the water, calculate the time taken to heat 5 kg water from 30°C to 100°C.
A torch bulb is rated at 3 V and 600 mA. Calculate it’s
- power
- resistance
- energy consumed if it is used for 4 hours.
What is the meaning of electric power of an electrical device? Write its SI unit.
A conductor of 10 Ω is connected across a 6 V ideal source. The power supplied by the source to the conductor is ______.
