Two identical wires one of nichrome and other of copper are commented in series and current is passed through them. State the change observed in the temperature in the two wires. Justify your ans. State the law which explains the above observation.
Answers
Answer:
Explanation:
The temperature of nichrome wire will become very high because it is an alloy and has high resistivity.
This can be explained by joules law of heating which states that the heat produced in a resistor is directly proportional to the Square of the current flowing through it, directly proportional to the resistance of the resistor and directly proportional to the time for which the current flows through the resistor.
Answer:
Explanation:
The resistivity of nichrome is more than that copper, so its resistance is also high. Therefore large amount of heat is produced from nichrome wre for the same current as campared to that of copper wire. Accordingly more change in temperature is observed in the nichrome wire. This is explained by joules law of heating.
Joules law of heating states that the amount of heat produced in a conductor is :-
(i) Directly proportional to the square of current flowing through it, i.e
H ∝ I
(ii) Directly proportional to the resistances offered by the conductor to the current, i.e
H ∝ R
(iii) Directly proportional to the time for which current is flowing through it, i.e H ∝ t
Combining these, we get
H ∝ I²Rt
H = KI²Rt
where K is proportionality constant and SI system, it is equal to one.