A 200 ohm resistor, a voltmeter and a 2.0 V cell of negligible internal resistance are connected in series. The voltmeter reads 1.0 V. Find the resistance of the voltmeter and the current in the circuit.?

Question

Answer

Solution:

Given:
Resistance of the resistor (R) = 200 Ω
Voltage of the cell (V) = 2.0 V
Voltage across the voltmeter (Vv) = 1.0 V

To find:
Resistance of the voltmeter (Rv) and Current in the circuit (I)

Formula:
Total resistance in the circuit (Rt) = R + Rv
Ohm's law: V = IR

Calculation:

Total resistance in the circuit (Rt) = R + Rv
From Ohm's law, we know that V = IR. Therefore, the current (I) in the circuit can be calculated as:

I = V / Rt

Substituting the given values, we get:

I = 2.0 / (200 + Rv)

Voltage across the resistor (Vr) = V - Vv
Substituting the given values, we get:

Vr = 2.0 - 1.0 = 1.0 V

From Ohm's law, we know that V = IR. Therefore, the current (I) in the resistor can be calculated as:

I = Vr / R

Substituting the given values, we get:

I = 1.0 / 200 = 0.005 A

Substituting the value of I in the earlier equation, we get:

0.005 = 2.0 / (200 + Rv)

Solving for Rv, we get:

Rv = (2.0 / 0.005) - 200 = 400 - 200 = 200 Ω

Answer:
Resistance of the voltmeter (Rv) = 200 Ω
Current in the circuit (I) = 0.005 A

Answer

Let the resistance of voltmeter be R then it read 1 volt then
1 = i R (1) equation
from kirchoff law
2 =1 + 200 i so we get i = 1÷200
and R EQUALS TO 200 OHM

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