Exams › JEE Advanced › Physics
All rods in a diamond-shaped network (vertices A, B, O, C, D where A is at top, C at bottom, B at right, D at left, O at center) have the same thermal conductance K*A/a. Ends A and C are maintained at temperatures 2T0 and T0 respectively. Which of the following statements are correct? (A) The rate of heat flow through paths ABC, AOC, and ADC is the same. (B) The rate of heat flow through rods BO and OD is not the same. (C) The total rate of heat flow from A to C is 3KAT0/(2a). (D) The temperatures at junctions B, O, and D are all the same.
- (A) Rate of heat flow through ABC, AOC, and ADC is the same
- (B) Rate of heat flow through BO and OD is not the same
- (C) Total rate of heat flow from A to C is 3KAT0/(2a)
- (D) Temperatures at junctions B, O, and D are the same
Correct answer: (A) Rate of heat flow through ABC, AOC, and ADC is the same
Solution
Symmetry forces T_B = T_D = T_O = 3T0/2, making all three parallel paths equivalent with the same heat flow rate KAT0/(2a) each, giving a total of 3KAT0/(2a). Statements A, C, and D are correct; B is false because BO and OD also carry the same current by symmetry.
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]
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(P) 2000 K
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Group-II:
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