Two resistors of 100 each are connected in series with a 9 V battery. A voltmeter of 400 resistance is connected to measure the voltage drop across one of the resistors. The voltmeter reading is _ _ _ _ V.

Step-by-step solution

When the 400Ω voltmeter is connected in parallel with one 100Ω resistor, the equivalent resistance is R_ eq = 100 400 500 = 80Ω . Total circuit resistance: R_ total = 100 + 80 = 180Ω . Circuit current: I = 9/180 = 0.05 A. Voltmeter reading (voltage across parallel combination): V = 0.05 80 = 4 V