A. pin insulator
B. string insulator
C. strain insulator
D. all of the above
Answer: C. strain insulator
Explanation:
A strain insulator is an electrical insulator that is designed to work in mechanical tension (strain), to withstand the pull of a suspended electrical wire or cable.
They are used in overhead electrical wiring, to support radio antennas and overhead power lines.
Electrical insulators are used to hold conductors in position, separating them from one another and from surrounding structures.
They form a barrier between energized parts of an electric circuit and confine the flow of current to wires or other conducting paths as desired.
in type insulators are used for transmission and distribution of communications, and electric power at voltages up to 33 kV.
To support this lateral load, strain insulators are used. For low voltage lines (less than 11 kV), shackle insulators are used as strain insulators.
Overhead line insulators:
1. Pin insulators used up to 33 kV.
2. Suspension type insulators all voltages 33 kV to 765 kV.
3. Strain insulators are used in river/ road/ railway crossings and dead end end tower to reduce sag.
Strain insulator is one of the suspension insulator is used to reduce sag in the transmission lines connected between the two towers and it is practically used in railway crossings, road crossings, river crossings and in the dead end towers.