During boiling, temperature remains constant because heat is used to:
A. Increase pressure
B. Break intermolecular bonds
C. Increase kinetic energy
D. Expand volume
Answer: Option B
Solution (By JKExamLibrary)
At boiling point, supplied heat (latent heat) breaks intermolecular bonds for phase change, not increasing kinetic energy (temperature). Potential energy increases while kinetic energy (temperature) stays constant. Memory aid: 'Latent heat changes state, not temperature'. Conceptual question testing phase change understanding, common in competitive exams to assess microscopic interpretation.
What is the equivalent resistance when n identical resistors, each of resistance R, are connected in series, compared to when they are connected in parallel?
A.Parallel resistance is n² times the series resistance.
B.Series resistance is equal to the parallel resistance.
C.Series resistance is n times the parallel resistance.
D.Series resistance is n² times the parallel resistance.
Explanation:
When n resistors of resistance R are in series, Rs = nR. When connected in parallel, Rp = R/n. To find the ratio, Rs / Rp = (nR) / (R/n) = n². Therefore, the series resistance is n² times the equivalent parallel resistance. This is a highly frequent numerical shortcut for exams.
Explanation:
Convection requires medium, movement of hot and cold masses. Land/sea breeze, trade winds, heating water. Conduction vibration transfer without particle movement.
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