Question

What resistance must be placed in parallel with a 10.0-Ω galvanometer (100-μA sensitivity) for a 20.0-A full-scale reading?

A) 0.05 Ω
B) 0.2 Ω
C) 0.5 Ω
D) 2.0 Ω

Answer 1

The resistance that must be placed in parallel with the 10.0-Ω galvanometer for a 20.0-A full-scale reading is 199 Ω.

Step-by-step explanation:

To find the resistance that must be placed in parallel with the galvanometer, we can use Ohm's Law. Ohm's Law states that the current flowing through a resistor is equal to the voltage across the resistor divided by its resistance. Since the galvanometer has a sensitivity of 100 μA and the desired full-scale reading is 20 A, we can calculate the resistance as follows:

Resistance = Voltage / Current

Resistance = (20 A - 0.1 A) / 0.1 A

Resistance = 19.9 A / 0.1 A

Resistance = 199 Ω

Therefore, the resistance that must be placed in parallel with the galvanometer is 199 Ω.