Physics Practice: Heat Transfer (Mock Test 4 - Expert)
1. Expert Analysis: Why do ice cubes melt faster when salt is sprinkled on them, even if the surrounding temperature is below 0°C?
2. Clinical Logic: In a "Cryosurgery" procedure, why is liquid nitrogen used to destroy abnormal tissues?
3. Data-based: A metal rod of length $100 \text{ cm}$ is heated from $20^\circ\text{C}$ to $120^\circ\text{C}$. If $\alpha = 1.2 \times 10^{-5} \text{ } ^\circ\text{C}^{-1}$, the increase in length is:
4. Experimental Setup: Why is a "Davy’s Safety Lamp" enclosed in a fine wire gauge when used in mines?
5. Which of the following describes the "Lyman-Alpha" radiation cooling in high-atmosphere physics?
6. Why are telephone wires left slightly sagging between poles during summer?
7. A pyrometer is used specifically to measure:
8. In a "Convection experiment" using Potassium Permanganate, why does the color move upwards?
9. "Thermal Capacity" of a body is defined as the heat required to raise its temperature by:
10. Why is the "Ingen-Housz experiment" used in thermal physics?
11. A glass stopper stuck in a bottle neck can be removed by pouring hot water on the neck because:
12. Which physical quantity remains constant during a change of state (e.g., Ice melting)?
13. In the formula $Q = mc\Delta T$, 'c' represents:
14. Why is a person's breath visible on a cold winter morning?
15. The "Lower Fixed Point" of a Fahrenheit thermometer is:
16. Which of the following is an example of heat transfer by radiation in daily life?
17. $1 \text{ kcal}$ is exactly equal to:
18. Why does the "Bimetallic strip" in an electric iron snap the circuit?
19. If you heat a metal plate with a circular hole in the center, the diameter of the hole will:
20. Thermal equilibrium means two bodies in contact have the same:
