A voltage source having source impedance of 10 ohm in series with 10 mH inductance generates a sinusoidal signal of amplitude 10 V and angular frequency 10 rad/s. What should be the load to get the maximum power transferred?

This question was previously asked in
ISRO VSSC Technical Assistant 11 Feb 2024 Official Paper
View all ISRO Technical Assistant Papers >
  1. 10 Ω resistance
  2. 10 Ω in series with 10 mH inductance
  3. 10 Ω in series with 1F capacitance
  4. 10 Ω in series with 10 mF capacitance

Answer (Detailed Solution Below)

Option 3 : 10 Ω in series with 1F capacitance
Free
ISRO Technical Assistant Mechanical Full Mock Test
80 Qs. 80 Marks 90 Mins

Detailed Solution

Download Solution PDF

Explanation:

To achieve maximum power transfer, the load impedance must match the complex conjugate of the source impedance. In this problem, the source impedance is given as 10 Ω in series with 10 mH inductance. The complex impedance of the source can be expressed as:

Zsource = R + jωL

Here:

  • R = 10 Ω (resistance)
  • L = 10 mH = 0.01 H (inductance)
  • ω = 10 rad/s (angular frequency)

Substituting the values:

Zsource = 10 + j(10 × 0.01) = 10 + j0.1 Ω

The complex conjugate of the source impedance is:

Zload = R - jωL = 10 - j0.1 Ω 

To match this impedance, the load should consist of a 10 Ω resistor in series with a capacitive reactance that cancels out the inductive reactance of the source. The capacitive reactance is given by:

XC = -XL = -ωL

XC = -0.1 Ω

The reactance of a capacitor is related to its capacitance by the formula:

XC = 1 / (ωC)

Substituting the values:

-0.1 = 1 / (10 × C)

C = 1 / (10 × 0.1) = 1 F

Thus, the load impedance that matches the complex conjugate of the source impedance is a 10 Ω resistor in series with a 1 F capacitor. Therefore, the correct answer is Option 3.

Latest ISRO Technical Assistant Updates

Last updated on May 30, 2025

-> The ISRO Technical Assistant recruitment 2025 notification has been released at the official website. 

-> Candidates can apply for ISRO recruitment 2025 for Technical Assistant from June 4 to 18.

-> A total of 83 vacancies have been announced for the post of Technical Assistant.

-> The Selection process consists of a written test and a Skill test.

-> Candidates can also practice through ISRO Technical Assistant Electrical Test Series, ISRO Technical Assistant Electronics Test Series, and ISRO Technical Assistant Mechanical Test Series to improve their preparation and increase the chance of selection. 

Hot Links: all teen patti master teen patti rich teen patti joy official teen patti download teen patti master update