Question

In an electrical circuit, ammeter reads 0.9 A .If another resistor of 2 ohms is connected in

series to the circuit ,the reading of the ammeter is :​

Answer 1

ANSWER

In the circuit shown, when key K is open branch BC will not be a part of the circuit (i.e. not connected to the circuit having battery ). The current will not flow through the branch BC having 4Ω resistor. Hence the ammeter will read the current flowing through remaining circuit.

Therefore,

I=

R

V

I=

5

10

I=2A

Answer 2

Answer:

From the figure,

Voltage,V=6V

Current,I=2A

Resistor 3 ohms and 6 ohms are in parallel.

So,

1/r=1/2+1/6

r=2

Now,2 ohms and r are in series,so

R=2+r

Since,

R=V/1

2+r=6/2

r=1

Explanation:

Hope it helps!