Question

if ammeter reads 2A and voltmeter reads 120V for 75 ohm resistance then what is the resistance of the voltmeter

Answer 1

Answer:

300ohm is the answer

Explanation:

use formula

V=I(Rr/R+r)

where R is resistance in conductor

r is resistance of voltmeter

Answer 2

Answer:

The resistance of the voltmeter is 300Ω.

Explanation:

To answer, we'll use the formula shown below:

$V=I(\frac{Rr}{R+r})$       (1)

Where,

V=voltage reading of the voltmeter

I=current reading of the ammeter

R=resistance of the resistor

r=resistance of the voltmeter

From the question we have,

The current reading of the ammetr=2A

The voltage reading of the voltmeter=120V

The resistance of the resistor=75Ω

We obtain this by entering the numbers in equation (1);

$120=2\times (\frac{75r}{75+r})$

$60= (\frac{75r}{75+r})$

$60(75+r)=75r$

$75r-60r=4500$

$15r=4500$

$r=300\ \Omega$

The resistance of the voltmeter is 300Ω.

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