Question

for the shown arrangement of identical resistors connected across a constant voltage supply the current entering the arrangement, when resistor 2 is removed from the circuit, changes by​

Answer 1

Answer:

The 3 ohm resistance and 7 ohm resistance in series so net resistance will 10 ohm then this 10 ohm resistor

Answer 2

Given :

1) Intial current in the circuit = 9 A

2) Constant voltage supply

To find :

1) Change in current after removal of resistor R2

Solution :

• In first case, all three resistors are connected in parallel

1/Req = 1/R + 1/R + 1/R

1/Req = 3/R

• Req = R/3

• According to Ohm's Law,

i.e V = IR

and I = V/R

We can say that I is inversely proportional to R.

• For second case, Resistor 2 is removed.

Now, Resistor 1 and Resistor 3 are in parallel combination.

1/Req' = 1/R + 1/R

1/Req' = 2/R

• Req' = R/2

We can write,

I' / I = Req / Req'

I' = Req×I / Req'

I' = (R/3)×9 / (R/2)

I' = (9/3) / (1/2)

I' = 3×2 = 6 A

Change in current = I - I' = 9A - 6A

∆I = 3A

Answer : Change in current, when resistor 2 is removed is 3A