In Circuit-$1$ and Circuit-$2$ shown in the figures, $R_1=1\Omega$, $R_2=2\Omega$ and $R_3=3\Omega$. P 1 and…

In Circuit-$1$ and Circuit-$2$ shown in the figures, $R_1=1\Omega$, $R_2=2\Omega$ and $R_3=3\Omega$. P1 and P2 are the power dissipations in Circuit-1 and Circuit-2 when the switches S1 and S2 are in open conditions, respectively.
Q1 and Q2 are the power dissipations in Circuit-1 and Circuit-2 when the switches S1 and S2 are in closed conditions, respectively.

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Which of the following statement(s) is(are) correct?

  1. When a voltage source of 6V is connected across A and B in both circuits, P1<P2
  2. When a constant current source of 2Amp is connected across A and B in both circuits, P1>P2
  3. When a voltage source 6V is connected across A and B in Circuit-1Q1>P1
  4. When a constant current source of 2 Amp is connected across A and B in both circuits, Q2<Q1

Solution

When S1 and S2 are open

For circuit 1

Req1=1+5×125+12=1+511=1611 Ω

P1=V2Req=6216×11=36×1116=24.75 W

For circuit 2

Req2=611 Ω

P2=V2Req=626×11=36×116=66 W

Therefore, P2>P1

Option A is correct

  If 2 A source is used in both cases.

P1=i2Req 1=22×1611=6411=5.818 W

P2=i2Req2=(2)2×611=2411=2.1818 W

P1>P2

Option B is correct.

When S1 and S2 are closed

For Q1

Req=511Ω

Q1=V2Req=62511=36×115=79.2 W

P1=24.75 W

Therefore, Q1>P1

Option C is correct.

For option D

Q1=i2Req=22×511=2011=1.81 W

Q2=i2Req=22×12=42=2 W

Q2>Q1

Option D is incorrect.

Asked in: JEE Advanced 2022 (Paper 2)

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