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Electromagnetic Induction — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Induction1 Mark
Question
Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b ), (c) and (d) as given below.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and Rare true but R is NOT the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): When number of turns in a coil doubled, coefficient of self inductance of the coil becomes four times.
Reason (R): Coefficient of self inductance is proportional to the square of number of turns.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.
Explanation:

The coefficient of self inductance of the coil is given by $\text{L}=\frac{\mu_0\text{N}^2\text{A}}{\text{l}}$

where N is number of turns, l is length of the coil and A is area of coil, so $\text{L}\propto\text{N}^2.$

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