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In case the communication cables are to be laid parallel to power cables, the distance between the two should be at least
0.5 m
2 m
4 m
0.05 m
0.5 m
When communication cables (such as telephone or fiber optic cables) are laid parallel to power cables, a minimum clearance of 0.5 meters must be maintained. This distance is essential to minimize electromagnetic interference (EMI) and inductive coupling, which can disrupt communication signals.
When communication cables (such as telephone or fiber optic cables) are laid parallel to power cables, a minimum clearance of 0.5 meters must be maintained. This distance is essential to minimize electromagnetic interference (EMI) and inductive coupling, which can disrupt communication signals.
E=тИТNdtd╬жтАЛ тАФ Faraday's Law indicating induced voltage due to magnetic field variation
MтИЭd1тАЛ тАФ Mutual inductance reduces as separation distance 'd' increases
The proximity of power cables carrying alternating current generates a time-varying magnetic field around them. According to Faraday's Law of Induction, this magnetic field induces unwanted electromotive forces (EMF) in nearby conductors, causing crosstalk or signal degradation in communication lines. Maintaining a distance of 0.5 meters significantly reduces the intensity of this magnetic flux coupling at the communication cable path.
Minimum clearance is 0.5 meters for parallel runs.
Inductive interference is the primary concern for communication lines.
Higher voltage power lines may require even greater separation based on local grid safety codes.
Shielding of communication cables can sometimes mitigate interference if strict distance is not possible.
Reduces signal-to-noise ratio degradation
Prevents transient power surges from damaging sensitive communication hardware
Complies with safety standards for electrical infrastructure
Requires wider trenching space
Increases project footprint and excavation costs
Underground utility corridors
Industrial plant cabling
Telecommunication duct banks near electrical substations
Indian Standard IS 1255 provides guidelines for installation and maintenance of underground power cables.
Option D (0.05 m) is physically unsafe and creates severe electromagnetic coupling risks.
Options B and C represent distances that exceed the minimum requirement, which is safe but often uneconomical due to space constraints.
A is correct тАФ A minimum separation of 0.5 meters is required to mitigate electromagnetic interference between parallel power and communication lines.
Always remember that in power transmission, maintaining spatial separation is the first line of defense against noise; shielding is the secondary technical solution.