Assertion (A): Kirchhoff’s loop law represents conservation of energy.
Reason (R): If the sum of “Potential Differences” around a closed loop is not zero, unlimited energy could be gained by repeatedly carrying a charge around a loop.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
Kirchhoff's loop law states that the algebraic sum of changes in potential around any closed loop is zero, which is a direct consequence of the conservation of energy. If this sum were not zero, it would imply energy creation or destruction, violating energy conservation. Thus, both (A) and (R) are true, and (R) correctly explains (A).
Assertion (A): The bending of an insulated wire increases the resistance of wire.
Reason (R): The drift velocity of electrons in bent wire decreases.
1. (1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. (2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (3) (A) is true but (R) is false
4. (4) Both (A) and (R) are false
View Answer
Resistance of a wire \( R = \rho \frac{L}{A} \) primarily depends on its resistivity \( rho \), length \( L \), and cross-sectional area \( A \). Bending an insulated wire does not significantly alter these properties, so its resistance does not increase. Drift velocity is not affected by bending either. Therefore, both (A) and (R) are false.
Consider the following statements and choose the correct option.
Statement (A): Kirchhoff’s junction law follows the conservation of charge.
Statement (B): Kirchhoff’s loop law follows the conservation of energy.
1. Only statement (A) is correct
2. Only statement (B) is correct
3. Both statements are correct
4. Both statements are incorrect
View Answer
Kirchhoff's first law (junction rule) is based on the law of conservation of charge, while the second law (loop rule) is based on the law of conservation of energy. Both statements are correct.