Given:
- Resistance of galvanometer:
- Series resistance:
- Voltage measured:
Step 1: Calculating the Current through the Galvanometer
The current through the galvanometer, , is given by:
Step 2: Converting the Galvanometer to an Ammeter
To convert the galvanometer into an ammeter that can read up to 10 A, we need to connect a shunt resistance in parallel with the galvanometer. The shunt resistance is given by:
where is the total current.
Rearranging for :
Simplifying:
Step 3: Expressing in the Required Form
Given that , we have:
Therefore, the value of is 20.
For the circuit shown above, the equivalent gate is: