A voltmeter with internal resistance 100 Ohm and ammeter wit

A voltmeter with internal resistance 100 Ohm and ammeter with internal resistance 1 Ohm are used for the measurements of the voltage across the resistor R1 and current in the resistor R2. Calculate readings of the devices.

Solution

Here ,

R1 = 16 Ohm

R2 = 5 Ohm

Rext = 100 Ohm

for the reading in devices

R1\' = 100 * 16/(100 + 16) = 13.8 Ohm

R2\' = 5 + 1 = 6 Ohm

Now , voltage across the R1 = 13.8 * 12/(13.8 + 6)

voltage across the R1 = 8.36 V

current in Resistor R2 = 12/(6 + 13.8)

current in Resistor R2 = 0.61 A

the current in resistor R2 , ammeter reading is 0.61 A