Question

heyy guys... please solve it✌✌✌..Don't look at answer.i just need explanation with solution...​

Answer 1

Answer:The ANS. IS 5.

Explanation:

Doesn't  matter the key is closed as voltage across parallel resistance is equal so by-  V=IR,  I=5ohm. (An Ammeter shows current)

Answer 2

When the key is open the 5 ohm resistor is not connected to the circuit so the current will flow only through the 4 ohm resistor

Voltage of cell = 20 V

So the current flowing through the circuit will be

I = V / R

I =20 /4

I = 5 A

When the key is closed the current will flow through both the resistors

the net resistance will be,

Rp = 5×4/9=20/9

Rp = 2.22 ohm

Total current flowing through the circuit

I = V /Rp

I =20/2.22

I=9 A

We know that the potential difference of the resistors connected in parallel is the same

the ammeter will show the current flowing through the 4 ohm resistor only

Current flowing through 4 ohm resistor

I 1= V /R

I 1=20 /4

I 1 = 5 A

( the current flowing through 5 ohm resistor will be I 2= I - I 1 =9-5 =4 A )