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
The skin effect cause
Portion of the conductor near the surface carries less current and core of the conductor carries more current
Portion of the conductor near the surface carries more current and the core of the conductor carries less current
Current flows through the half cross-section of the conductor
None of the above
Portion of the conductor near the surface carries more current and the core of the conductor carries less current
The skin effect is the phenomenon in AC systems where current density is non-uniformly distributed across the cross-section of a conductor. It results in a higher current concentration near the surface of the conductor, effectively reducing the internal area available for current flow.
The skin effect is the phenomenon in AC systems where current density is non-uniformly distributed across the cross-section of a conductor. It results in a higher current concentration near the surface of the conductor, effectively reducing the internal area available for current flow.
RacтАЛ=RdcтАЛ├Ч(1+k) тАФ where k is a factor depending on frequency and conductor size
╬┤=╧Й╬╝2╧БтАЛтАЛ тАФ skin depth, the depth at which current density drops to 1/e of its surface value
As AC flows through a conductor, it creates a time-varying magnetic field. This field induces eddy currents within the conductor that oppose the main current flow at the center (where magnetic flux linkage is maximum) and aid it near the surface. Consequently, the conductor exhibits an effective increase in internal resistance as the frequency increases.
Skin effect is directly proportional to frequency, conductor diameter, and permeability of the material.
It is non-existent in DC circuits because DC creates a constant magnetic field, leading to uniform current distribution.
Causes an increase in effective resistance, leading to higher I2R power losses.
More pronounced in larger diameter conductors.
Increased effective resistance (RacтАЛ>RdcтАЛ)
Higher transmission power losses due to heat
Reduced effective cross-sectional area utilization
Designing high-voltage AC transmission lines using ACSR (Aluminum Conductor Steel Reinforced) to minimize cost and weight.
High-frequency communication and radio frequency (RF) design.
The skin effect is negligible for DC but becomes significant for high-frequency applications like power transmission (50/60 Hz) and communication.
Option A describes the reverse of the actual phenomenon (internal current crowding).
Option C is incorrect because current does flow through the entire conductor, just with varying density.
B is correct тАФ Due to the self-inductance of the conductor, the magnetic flux linkages are higher at the center, causing the current to be pushed toward the outer surface.
Always remember that skin effect increases with frequency; hence, for high-frequency applications, hollow conductors are preferred to optimize material usage and weight.