Galvanometer as Ammeter – Rankers Physics

Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ): Practice Problem & Solution

Assertion (A): A galvanometer can be used as an ammeter only. Reason (R): A galvanometer can be used in electric circuit to detect the electric current only.  
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Measuring Devices ( Galvanometer, Voltmeter and Ammeter & Meter Bridge ). Understanding the underlying formula is key to arriving at the correct answer below:

A galvanometer is a device used to detect small electric currents. It can be converted into an ammeter by connecting a low resistance shunt in parallel or into a voltmeter by connecting a high resistance in series. Therefore, the assertion that it can be used 'only' as an ammeter is false, and the reason that it can be used to detect current 'only' is also false. Thus, both A and R are false.

Leave a Reply

Your email address will not be published. Required fields are marked *

Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. A galvanometer has a coil of resistance $100 \Omega$ and gives a full scale deflection for $30 \text{ mA}$ current. If it is to work as a voltmeter of $30 \text{ V}$ volt range, the resistance required to be added will be : (2010 Pre)
2. A copper wire of length $10 \text{ m}$ and radius $(10^{-2}/\sqrt{\pi}) \text{ m}$ has electrical resistance of $10 \Omega$. The current density in the wire for an electric field strength of $10 \text{ V/m}$ is: (2022)
3. A copper wire of radius 1 mm contains \(10^{22}\) free electrons per cubic metre. The drift velocity for free electrons when 10 A current flows through the wire will be (Given, charge on electron \(= 1.6 \times 10^{-19} \text{C}\))
4. Assertion (A): In series combination of electrical bulb, lower power bulb emits more light than that of higher power bulb. Reason (R): The lower power bulb in series gets more current than the higher power bulb.  
5. A carbon resistor of $(47 \pm 4.7)\text{ k}\Omega$ is to be marked with rings of different colours for its identification. The colour code sequence will be (2018)