The voltmeter depicted in the figure measures a potential difference of 18 V across the 50 resistor. Determine the resistance of the voltmeter.

Step-by-step solution

Given the potential difference across the parallel combination is V_p = 18 V . The potential difference across the 24 resistor is: V₂₄ = 30 - 18 = 12 V The current in the main circuit is: I = 12 24 = 0.5 A Let R_V be the resistance of the voltmeter. The equivalent resistance of the parallel part is: R_p = 18 0.5 = 36 For the parallel combination: 1 R_p = 1 50 + 1 R_V 1 36 = 1 50 + 1 R_V 1 R_V = 1 36 - 1 50 = 25 - 18 900 = 7 900 R_V = 900 7 128.6 The closest option to this value is 130 . Answer: 130