Question

the reading of the ammeter is 3.0 ampere find the current through the 10 ohm and 20 ohm resistor

Answer 1

Here is your answer
Current in 10ohm resistor = 2A
Current in 20ohm resistor = 1A

Answer 2

Answer:

taking the the equivalent resistance of 10ohm and 20ohm

as they are in parallel

the r=6.6ohm

after this we know I=3.0A

so v=IR

v=6.6x3.0

v=19.8approx

taking v=20volts

so now we know v=20v

r= 10ohm

I =v/r

l=20/10

2A for case 1

and I =v/r

for case 2

r=20ohm

I=v/r

I=20/20

I =1A

for 10ohm I= 2A

and for 20ohm I = 1A