Question

Assertion :Current is passed through a metallic wire, heating it red. Half of its portion is cooled by cold water jacket, then rest of the half portion become more hot. Reason: Resistances decreases due to decrease in temperature and so current through wire increases.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

$R^{1}R(1+\alpha \Delta T)$

if $\Delta T\downarrow$

then $R^1\downarrow$

$\therefore$ Current through wire increases.

$\therefore$ Ans $\to$ (A)