Question

What will be the potential difference measured by an ideal voltmeter in the circuit of the figure?​

Answer 1

The voltage across 150 ohm resistor is 6 volts.

Step-by-step explanation:

Given that,

Resistors having resistances 150 ohms and 300 ohms are in series. Their equivalent is :

R = 150 + 300

R = 450 ohms

Let I is the current in the circuit. Using Ohm's law,

V = IR

`I=(V)/(R)\\\\I=(18)/(450)\\\\I=0.04\ A`

The current in series remains the same while potential divides. So,

`V_1=IR_1\\\\V_1=0.04* 150\\\\=6\ V`

So, the voltage across 150 ohm resistor is 6 volts.