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प्रश्न
What is the commercial unit of electrical energy? Represent it in terms of joules.
उत्तर
The commercial unit of electrical energy is Kilowatt hour (kWh)
1 kWh = 1000 W × 1 h
`1 "kWh" = 1000 "J"/"s" × 3600 "s"`
1 kWh = 3.6 × 106 J
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संबंधित प्रश्न
The commercial unit of energy is :
(a) watt
(b) watt-hour
(c) kilowatt-hour
(d) kilo-joule
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 current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V.
calculate:
(i) the resistance of the wire and
(ii) the heat energy produced in 1 minute.
An electric bulb, when connected across a power supply of 220 V, consumes a power of 60 W. If the supply drops to 180 V, what will be the power consumed? If the supply is suddenly increased to 240 V, what will be the power consumed?
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Define Kilo watt hour.
Why is the heating element of an electric oven wound on a helix? State the reason.
A device is used to transform 12 V a.c. to 200 V a.c. What is the name of this device? Name the principle on which it works.
I ampere of current is passed through a resistor of resistance R ohm for time t second. Obtain expression for
(i) the electrical energy, and
(ii) the electrical power spent.
