Exam Question
With the aid of circuit diagram, explain how a galvanometer can be used as an ammeter (16)
Class 4 (4th Engineer)
MET
📅 Feb 2023
Reference Answer
### 1. Fundamental Principle of a Galvanometer
A galvanometer is a highly sensitive instrument designed to detect and measure very small electric currents, typically in the microampere or milliampere range. Its core limitations are:
* **Low Current Capacity:** A small current, known as the full-scale deflection current ($$I_g$$), is sufficient to cause its pointer to move to the maximum position on its scale. Any current significantly larger than this will damage or destroy the delicate coil winding.
* **Internal Resistance:** The galvanometer coil has a specific internal resistance, denoted as $$G$$.
A galvanometer is a highly sensitive instrument designed to detect and measure very small electric currents, typically in the microampere or milliampere range. Its core limitations are:
* **Low Current Capacity:** A small current, known as the full-scale deflection current ($$I_g$$), is sufficient to cause its pointer to move to the maximum position on its scale. Any current significantly larger than this will damage or destroy the delicate coil winding.
* **Internal Resistance:** The galvanometer coil has a specific internal resistance, denoted as $$G$$.
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