Assertion : Through the same current flows through the line wires and the filament of the bulb but heat produced in the filament is much higher then that in line wires.
Reason : The filament of bulbs is made of a material of high resistance and high melting point.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is NOT the correct explanation of A
C. A is true but R is false
D. A is false and R is true

Answer

A

Explanation

Heat produced `=H= i^(2)Rt`
`H prop R`
Since resistance of filament `gt gt` Resistance of wire so more heat is produced in filament. Therefore, Assertion is true. Filament is made of material having high resistance like tungsten so that heat produced is more.
Melting point of the material also should be high so that it can sustain more heat. Hence reason is also true. Reason properly explains the assertion.