Concepts Of Physics MCQ Edition [Volume 2]PhysicsSemiconductors and Semiconductor Devices
Every resistance shown in the figure has a value of 20 . Determine the equivalent resistance between points A and B . Does this value depend on whether point A or B is at a higher potential?
Options
- A40 , No
- B40 , Yes
- C20 , Yes
- D20 , No
Correct answer
D. 20 , No
Step-by-step solution
The given circuit can be analyzed as a Wheatstone bridge. Let the junction between the top two resistors be C and the junction between the bottom two resistors be D . The diode is connected between C and D . The resistance of each resistor is 20 . The ratio of resistances in the left arms is 20 20 = 1 , and the ratio in the right arms is also 20 20 = 1 . Since the ratios are equal, the Wheatstone bridge is balanced. Therefore, the potential at point C is equal to the potential at point D ( V_C = V_D ). Because ther