Discussion
Assertion (A) : Radiation resistance of an antenna is equal to the value of hypothetical resistance, that dissipates an equal amount of power, when a current is applied to the antenna.
Reason (R) : Radiation resistance of a short Hertzian dipole is given by \(R_{r} = 40\,\pi^{2}\left(\dfrac{dl}{\lambda}\right)^{2}\) ohms.
Answer: C
The assertion is true and the reason is false, option (C). The radiation resistance of an antenna is defined as the value of a hypothetical resistance that would dissipate the same power as the antenna radiates when it carries the same current, so the assertion is correct. For a short Hertzian dipole, the radiation resistance is \(R_{r} = 80\pi^{2}\left(\dfrac{dl}{\lambda}\right)^{2}\) ohms, so the figure of 40 in the reason is wrong; 40 gives half of the true value. Options (A) and (B) accept the reason and option (D) rejects the assertion, which is the standard definition.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development