Assertion (A): Though the same current flows through the line wires and the filament of the bulb but the rate of heat produced in the filament is much higher than that in line wires.
Reason (R): The filament of bulbs is made of a material of high resistance and low melting point.
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false
Solution:
Assertion (A) is true because heat produced is \( H = I^2 R t \) and the filament has a much higher resistance \( R \). Reason (R) is false because filaments (like tungsten) have a *high* melting point to withstand high temperatures.
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