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Two identical conducting rods are first connected separately, each bridging a vessel of water at 100 degree C and a vessel of ice at 0 degree C (rods used independently/in parallel). In the second case the two rods are joined end to end (in series) and bridge the same two vessels. Let q1 and q2 (g/s) be the rates of melting of ice in the first and second cases respectively. Find q2/q1.
- 1/2
- 2/1
- 4/1
- 1/4
Correct answer: 1/4
Solution
In the first (parallel) case the conductance is 2 times one rod; in the series case it is 1/2 of one rod. So q2/q1 = (1/2)/2 = 1/4.
Related JEE Advanced Physics questions
- Match the temperature of a blackbody listed in Group-I to the corresponding statement in Group-II, and select the correct answer.
[Given: Wien’s constant = 2.9 × 10⁻³ m-K and hc/e = 1.24 × 10⁻⁶ V-m]
Group-I:
(P) 2000 K
(Q) 3000 K
(R) 5000 K
(S) 10000 K
Group-II:
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(2) The peak wavelength of emitted radiation falls within the visible spectrum.
(3) The peak wavelength of emitted radiation produces the broadest central diffraction maximum in a single-slit setup.
(4) The energy radiated per unit area is one-sixteenth of that emitted by a blackbody at 6000 K.
(5) The peak wavelength of emitted radiation is suitable for imaging human bones.
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