Thermal Physics

Step 1: Concept
Wien's Displacement Law: .
Step 2: Analysis
.
Step 3: Conclusion
.
Final Answer: (A)

Step 1: Presence
Production of indicates the presence of carbon in the compound.
Step 2: Absence of Water
Lack of water ( ) production indicates the compound contains no hydrogen.
Step 3: Identification
Among the options, carbon tetrachloride ( ) contains carbon but no hydrogen. Chloroform ( ), methane ( ), and ethyl iodide ( ) all contain hydrogen.
Final Answer: (a)

Step 1: Write the expression for heat required.
The heat required is given by: where , and is the molar heat capacity.

Step 2: Set up the integral.
Substitute the expression for into the integral:

Step 3: Perform the integration.
Integrating from 10 K to 50 K: Substitute the limits:

Step 4: Final calculation.
The final heat required is approximately:

Step 1: Understanding the Concept:
Energy of hydrogen-like atom: eV. For H, ; for He , .
Step 2: Detailed Explanation:
.
.
Step 3: Final Answer:
Thus, energy = .

Step 1: . For , so .

Step 2: s.

Step 1: Understanding the Concept:
Heat lost by copper = Heat gained by ice (used to melt).
Step 2: Detailed Explanation:
Heat lost by copper: J
Mass of ice melted: kg
Approximate value matching option: kg, kg. Closest answer is .
Step 3: Final Answer:
Amount of ice melted kg.

Step 1: Understanding the Concept:
By Stefan's law, power radiated: . Energy in time is .
Step 2: Detailed Explanation:
K, m , s
Step 3: Final Answer:
Energy radiated per minute J.

Concept: Linear expansion: Area expansion:

Step 1: Given linear expansion.


Step 2: Area expansion.

Concept: Relation between Celsius and Fahrenheit:

Step 1: Set condition.


Step 2: Substitute.


Step 3: Solve.