Question

⇒ What will be the voltmeter reading of the circuit?​

Answer 1

Answer:

The ammeter is connected in series with the circuit. So its reading will show the value of the current flowing in the circuit. Hence, the reading of the ammeter is equal to 1A. Hence, the voltmeter will show a reading of 2V.

Answer 2

★ Solution :-

• The reading of the voltmeter will be 0 .

There are two basic reasons for this answer. In order to understand those reasons, we need to understand about Potential Difference and Voltmeter.

• Potential Difference ::

It is the work done in bring a unit positive charge from infinity to another point. It is given by the ratio of Workdone in bringing the charge by the magnitude of the charge. It is denoted by Volt (V) and sometimes referred to as Voltage. Voltmeter is used to measure Potential Difference between two points.

• Connection of Voltmeter ::

By the defination of Potential Difference, we see that it works only when it is connected to two points in the conductor. The reason is because the word 'Potential Difference' means the difference in 'Electrical Potential' between two points. This also means that for a proper working of Voltmeter in a circuit, it should be attached across a component at two different points in the circuit. This finally means that voltmeter should be connected in parallel across a component in the circuit. This component can be either wire, resistance, etc.

• Why voltmeter will give reading as 0 ?

• In the given circuit, Voltmeter is connected in series with the circuit. Already above we discussed, that in order to get reading of Potential Difference, it should be connected in parallel with circuit or circuit component. Here there will be no deflection in the needle of Voltmeter thus there will be no reading.

• Also, by defination of Potential Difference we know that, potential difference is calculated when we have two points and their Electrical Potential. Here since Voltmeter is connected in series it gives us only a single point. Thus we won't get reading of Voltmeter.

• We know that in parallel combination, potential difference across the components remain same. So voltmeter should be connected in parallel with circuit component.

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★ More to know :-

• Current : It is the amount of charge flowing through a conductor per unit time. It is denoted by I and it's S.I. unit is Ampere.

• Ammeter : It is the device used to measure the Current in the circuit. It is connected in series with circuit.

• Resistance : It is the potential difference across a piece of resistance per charge flowing through it per unit time. It is the property of a conductor to oppose the flow of current. It is denoted by R and it's S.I. unit is Ohm (Ω).

• Resistivity : It is the resistance offered by a conductor of unit length and unit area of cross - section.

• Resistor : It is the device that offers resistance.