Question

a voltmeter has a resistance 30ohm what will it's reading when when it is connected across a cell of emf eV having internal resistance 10 ohm solve step by step ​

Answer 1

Answer:

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Explanation:

Given: A voltmeter has a resistance 30Ω, a cell of emf 2 V, internal resistance 10Ω.

To find: Reading of voltmeter (V)

Solution: Now we know that current can be calculated as:

I = E / R+r

So, putting values in formula, we get:

I = 2/ 30 + 10

I = 2 / 40

I = 1/20 Amperes

Now we know the formula:

V = E - Ir

V = 2 - (1/20 × 10)

V = 2 - 1/2

V = 3/2

V = 1.5

So the Reading of voltmeter (V) is 1.5 V.