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NEET2026PhysicsChapterActual

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: When the length of a nichrome heating wire connected across a constant voltage supply is doubled, the heat produced per second by the wire is also doubled. Reason R: For a constant potential difference, the heat produced per second in a given wire is inversely proportional to its electrical resistance. I

Options

  1. ABoth A and R are true and R is the correct explanation of A.
  2. BBoth A and R are true but R is NOT the correct explanation of A.
  3. CA is true but R is false.
  4. DA is false but R is true.

Correct answer

D. A is false but R is true.

Step-by-step solution

The heat produced per second by a wire connected across a constant voltage supply V is given by P = V^2 R . For a constant potential difference, P 1 R . The heat produced per second is inversely proportional to the electrical resistance. Thus, Reason R is true. The resistance of a wire is given by R = l A . When the length l of the wire is doubled, its resistance R increases. Since the resistance increases, the heat produced per second P decreases. Therefore, the heat produced per second is not doubled, making Asse

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