Advertisements
Advertisements
प्रश्न
Establish the relation that heat produced in a metallic conductor due to the flow of current is V2t/R joules, where V is the potential difference across the ends of the conductor, R its resistance and t is the time in second for which current flows.
उत्तर
From the relation Q = Vit joule
Applying Ohm's law, V = iR
or i = V/R
Substituting the value of i, we get
Q = `"V" . "V"/"R" "t" = ("V"^2"t")/"R"` joule.
APPEARS IN
संबंधित प्रश्न
What determines the rate at which energy is delivered by a current?
What is consumed using different electrical appliances, for which electricity bills are paid?
State the S.I. unit of electrical power.
Name the physical quality which is measured in
(i) Kw (ii) kWh
A bulb of 40 W is used for 12.5 h each day for 30 days. Calculate the electrical energy consumed.
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.
What is the resistance, under normal working conditions of a 240 V electric lamp rated at 60 W? If two such lamps are connected in series across a 240 V mains supply, explain why each one appears less bright.
Mention three uses of the carbon arc.
What do you understand by ‘earthing’? What are the advantages of earthing in a household electric circuit? Explain, how it is done?
What is the meaning of electric power of an electrical device? Write its SI unit.
