Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
A DC source of EMF E volts and internal resistance R ohms is connected to a variable load and it is adjusted such that the load absorbs maximum power from the source. The current drawn from the source is:
The Maximum Power Transfer Theorem states that maximum power is transferred to a load when the load resistance (RLтАЛ) equals the internal resistance (R) of the DC source. Given RLтАЛ=R, the total circuit resistance becomes R+R=2R.
The Maximum Power Transfer Theorem states that maximum power is transferred to a load when the load resistance (RLтАЛ) equals the internal resistance (R) of the DC source. Given RLтАЛ=R, the total circuit resistance becomes R+R=2R.
Think of it like matching the impedance of a water pump to the size of the pipe; if the pipe is too narrow (high resistance) or too wide (low resistance), you don't get the most efficient flow of water (power) reaching the end.
Remember 'R-Load equals R-Internal' for Maximum Power Transfer.
I=RLтАЛ+REтАЛ тАФ Ohm's Law for a circuit with internal resistance
PLтАЛ=I2RLтАЛ тАФ Power delivered to the load
RLтАЛ=R тАФ Condition for Maximum Power Transfer
According to Ohm's Law, current I is given by I=RtotalтАЛEтАЛ. Under the condition for maximum power transfer, RLтАЛ=R, so the current flowing through the circuit is I=R+REтАЛ=2REтАЛ.
Maximum power is transferred when load resistance matches source internal resistance.
The total resistance of the circuit at maximum power transfer is exactly twice the internal resistance.
The efficiency of power transfer at the maximum power condition is exactly 50%.
Used in impedance matching for signal transmission in communication circuits.
The circuit is only 50% efficient at this point, as half the power is dissipated as heat within the source itself.
Audio amplifier to speaker impedance matching.
Radio frequency (RF) antenna matching circuits.
At maximum power transfer, the voltage across the load is half the EMF, i.e., VLтАЛ=2EтАЛ.
Option B (2REтАЛ) is the correct derivation based on the series combination of resistances.
B is correct тАФ By the Maximum Power Transfer Theorem, the load resistance must equal the internal resistance, leading to a total resistance of 2R and a resulting current of 2REтАЛ.
Always verify if the circuit asks for maximum power transfer or maximum efficiency; efficiency is maximized at infinite load resistance (zero current), whereas power is maximized at finite load resistance.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants