Advertisements
Advertisements
प्रश्न
How is the amount of heat produced calculated due to the passage of current in a metallic conductor? Derive an expression for it.
Advertisements
उत्तर
It is calculated by finding the amount of work done in sending the current through the conductor.
Let a current of i ampere flow in conductor having a potential difference of V volt across its ends for t second.
If Q be the amount of charge that flows in the conductor in t second.
Then Q = i × t coulomb
Since the amount of work done in: moving a charge Q across the ends of a conductor is W.
then W = Q × V joule
i.e., = i × t × V = Vit joule
or, the amount of heat produced Q = V it joule.
संबंधित प्रश्न
Define 1 kilowatt hour.
What is the current in the circuit shown (Fig. )
Mention three uses of the carbon arc.
‘The current rating of a fuse is 5A’. Comment on this statement.
What is the resistance of an appliance rated at V volt, P watt?
An Electric bulb is marked 100 W, 230 V. What how long would this lamp take to consume one unit of electricity?
Out of the three fuses with current ratings 5A, 10A, 15A, which one is to be connected in a geyser circuit marked 3 kW, 220V? Give reason for your answer.
1 kWh = ____________
A room has AC run for 5 hours a day at a voltage of 220V. The wiring of the room consists of Cu of 1 mm radius and a length of 10 m. Power consumption per day is 10 commercial units. What fraction of it goes in the joule heating in wires? What would happen if the wiring is made of aluminium of the same dimensions?
`[ρ_(Cu) = 1.7 xx 10_(Ωm)^-8, ρ_(Al) = 2.7 xx 10^-8 Ωm]`
