No of disc required for 11 kV transmission line = 1 disc Since the transmission line is 3-phase, therefore, the number of discs required for a single-pole will be 3. Total no. of poles = 80 No of disc = 3 × 80 = 240
Magnetic Field Strength (H) gives the quantitative measure of strongness or weakness of the magnetic field. H = B/μo Where B = Magnetic Flux Density μo = Vacuum Permeability The magnetic Field strength at the center of circular loop carrying current I is given by B = μoI/2r B/μo = I/2r H = I/2r At/m Where r = Radius
Skin Effect The steady direct current distributes itself uniformly over the whole section of a conductor but the alternating current does not distribute uniformly rather than it tends to concentrate near the surface of a conductor. In fact in the AC system, no current flows through the core and the entire current is concentric at the surface regions. This phenomenon is called skin effect. The skin effect causes the effective resistance of the conductor to increase with the frequency of the current. The skin effect is due to eddy currents set up by the AC current. The skin effect has practical consequences in the design of radiofrequency and microwave circuits and to some extent in AC electrical power transmission and distribution systems.
EXAMIANS