KVPY2017PhysicsCurrent Electricity
A uniform metallic wire of lenght L is mounted in two configurations. In configuration I (triangle), it is an equilateral triangle and a voltage V is applied to corners A and B. In configuration 2 (circle), it is bent in the form of a circle, and the potential v is applied at diameterically opposite points P and Q . The ratio of the power dissipated in configuration 1 to configuration 2 is.
Options
- A2 / 3
- B9 / 8
- C5 / 4
- D7 / 8
Correct answer
B. 9 / 8
Step-by-step solution
R = A ( R ₁= 3 ~A ) 1 R _ ep 1 2 R ₁ + 1 R ₁ 2 R _ eq = 2 R ₁ 3 = 2 3 3 ~A i ₁= V R _ eq = V 2 e 9 ~A R _ eq R 2 1 2 ( . / 2 ~A ) i ₂= V R _ eq V 4 ~A i ₁ i ₂ = 9 8