Question

With proper steps please..
attachment the answer if needed​

Answer 1

Given,

EMF (ε) of the cell = 2 volt

internal resistance (r) = 1 Ω

external resistance (R) = 4 Ω

Concept : Ammeter  measures the current in a circuit.

and, Voltmeter measures electric potential difference between two points in an electric circuit.

i) when key is open

Ammeter reading will be zero as no current will be passing thorough the circuit.

Voltmeter reading will be there due to emf only as current is 0.

So, Voltmeter reading can be given as:

V = ε - ir

V = 2 - 0*1

V = 2 Volt.

Voltmeter reading = 2 volt.

ii) when key is closed

Ammeter reading = I = ε / (R+r)

or, I = 2 / (1+4) = 2/5

or, I = 0.4 ampere

Voltmeter reading:

V = ε - Ir

V = 2 - 0.4*1

V = 2 - 0.4

V = 1.6 volt

Answer 2

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Given,

EMF (ε) of the cell = 2 volt

internal resistance (r) = 1 Ω

external resistance (R) = 4 Ω

Concept :

Ammeter  measures the current in a circuit.

and, Voltmeter measures electric potential difference between two points in an electric circuit.

i) when key is open

• Ammeter reading will be zero as no current will be passing thorough the circuit.
• Voltmeter reading will be there due to emf only as current is 0.

So, Voltmeter reading can be given as:

V = ε - ir

V = 2 - 0*1

V = 2 Volt.

Voltmeter reading = 2 volt.

ii) when key is closed

Ammeter reading = I = ε / (R+r)

or, I = 2 / (1+4) = 2/5

or, I = 0.4 ampere

Voltmeter reading:

V = ε - Ir

V = 2 - 0.4*1

V = 2 - 0.4

V = 1.6 volt