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MHT CET Medical202624 April 2026Evening ShiftPhysicsElectromagnetic InductionActual

The self inductance L of a solenoid of length l and area of cross-section A, with a fixed number of turns N increases as

Options

  1. Aboth l and A increase.
  2. Bl decreases and A increases.
  3. Cl increases and A decreases.
  4. Dboth l and A decrease.

Correct answer

B. l decreases and A increases.

Step-by-step solution

The self-inductance of a long solenoid is given by the formula: L = ₀ N^2 A l where N is the total number of turns, A is the cross-sectional area, and l is the length of the solenoid. Since the number of turns N is fixed, the self-inductance L is directly proportional to the area of cross-section A and inversely proportional to the length l . L A l Thus, to increase the self-inductance L , the area A must increase and the length l must decrease. Answer: l decreases and A increases.

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