Question

Assertion (A): Specific heat capacity of a substance X is 3.8 Jg⁻¹ K⁻¹ and of the substance Y is 0.4 Jg⁻¹ K⁻¹.

Reason (R): For the same heat energy and same mass, the rise in temperature of X will be more than Y, thus, X is a good conductor of heat.

Options

• Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

• Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).

• Assertion (A) is false, but Reason (R) is true.

• Assertion (A) is true, but Reason (R) is false.

Answer 1

Assertion (A) is true, but Reason (R) is false.

Explanation:

The assertion is true: the given values are simply two different specific heat capacities. The reason is false. For the same heat energy (Q) and mass (m), the temperature rise is $$\Delta T = \frac{Q}{mc}$$. Since c_X = 3.8 Jg⁻¹ K⁻¹ is greater than c_Y = 0.4 Jg⁻¹ K⁻¹, X will show a smaller rise in temperature than Y, not a greater rise. Also, high specific heat capacity does not mean good thermal conductivity; these are different properties.