R is the resistance box, V is the ideal voltmeter, when the resistance box is R1 = 2 ohm, the voltmeter reading is U1 = 4V, when the number of resistance boxes is R2 = 5 ohm, the number of voltmeters is U2 R is the resistance box, V is the ideal voltmeter. When the resistance box is R1 = 2 ohm, the reading of the voltmeter is U1 = 4V. When the number of resistance boxes is R2 = 5 ohm, the number of voltmeters is U2 = 5V

R is the resistance box, V is the ideal voltmeter, when the resistance box is R1 = 2 ohm, the voltmeter reading is U1 = 4V, when the number of resistance boxes is R2 = 5 ohm, the number of voltmeters is U2 R is the resistance box, V is the ideal voltmeter. When the resistance box is R1 = 2 ohm, the reading of the voltmeter is U1 = 4V. When the number of resistance boxes is R2 = 5 ohm, the number of voltmeters is U2 = 5V

The voltmeter measures the voltage of the resistance box, that is, the external voltage. Then the current is I 1 = U 1 / R 1 = 4 / 2 = 2A; I 2 = u 2 / R 2 = 5 / 5 = 1A; the equations can be set up as follows: 4 + 2R = E (1) 5 + 1R = e (2) and R = 1 ohm e = 4 v

In a series circuit, resistance R1 = 4 ohm, R2 = 8 ohm, and voltage representation u = 2V. (U measures R1). If the voltmeter is connected to both ends of resistance R2
How big is the real number of the voltmeter?

In the series circuit, the voltage is proportional to the resistance, and the indication is u '. Then u' = 2U = 4V is obtained from u '/ u = R2 / R1 = 2 / 1