Maximum Power Transfer MCQs

Practice Maximum Power Transfer MCQs with four options, answers and explanations for focused Electronics & Telecommunication Engineering revision.

Question 1

Network TheoryMaximum Power Transfer

For a DC resistive Thevenin network, maximum power is transferred to the load when RL is?

AZero
BEqual to Rth
CTwice Rth
DInfinite

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Correct Answer: B. Equal to Rth

Explanation: For a resistive DC network, maximum load power occurs when RL = Rth.

Reference: Standard network theory: maximum power transfer

Question 2

Network TheoryMaximum Power Transfer

A Thevenin source has Vth = 10 V and Rth = 5 ohm. If RL = 5 ohm, the load current is?

A0.5 A
B1 A
C2 A
D5 A

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Correct Answer: B. 1 A

Explanation: Total series resistance is 5+5=10 ohm, so I = 10/10 = 1 A.

Reference: Standard network theory: maximum power transfer

Question 3

Network TheoryMaximum Power Transfer

For the previous case with Vth = 10 V, Rth = 5 ohm and RL = 5 ohm, the load power is?

A1 W
B2.5 W
C5 W
D10 W

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Correct Answer: C. 5 W

Explanation: The load current is 1 A, so PL = I^2RL = 1^2×5 = 5 W.

Reference: Standard network theory: maximum power transfer

Question 4

Network TheoryMaximum Power Transfer

In a DC resistive network, maximum power is transferred to a variable load RL from a Thevenin source when?

ARL=0
BRL=Rth
CRL=2Rth
DRL tends to infinity

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Correct Answer: B. RL=Rth

Explanation: For a purely resistive Thevenin equivalent, load power is maximum when the load resistance equals the Thevenin resistance.

Reference: Standard network theory: maximum power transfer

Question 5

Network TheoryMaximum Power Transfer

A Thevenin equivalent has Vth=20 V and Rth=5 ohm. The maximum power available to a resistive load is?

A5 W
B10 W
C20 W
D80 W

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Correct Answer: C. 20 W

Explanation: Pmax=Vth^2/(4Rth)=400/(20)=20 W.

Reference: Standard network theory: maximum power numerical

Question 6

Network TheoryMaximum Power Transfer

For an AC network with Thevenin impedance Zth=4+j3 ohm, maximum average power is transferred to the load when ZL equals?

A4+j3 ohm
B4-j3 ohm
C3-j4 ohm
D7 ohm

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Correct Answer: B. 4-j3 ohm

Explanation: Maximum average power transfer in AC occurs for conjugate matching: ZL=Zth*=4-j3 ohm.

Reference: Standard network theory: conjugate matching