CL wadhwa bits solutions (106-110)

Lesson 18 of 21 • 32 upvotes • 14:58mins

Anvesh Sameer

106. Three insulating materials with breakdown strengths of 250 kV/cm, 200 kV/cm, 150 kV/cm and permittivities of 2.5, 3.0 and 3.5 are used in a single core cable. If the factor of safety for the materials is 5, the location of the materials with respect to the core of the cable will be: (a) 2.5, 3.0, 3.5 (b) 3.0, 2.5, 3.5 (c) 3.5, 3.0, 2.5 (d) 3.5, 2.5, 3.0.
     107. The coefficient of reflection of voltage for a short circuited line is: (a) 1.0 (b) – 1.0 (c) 0 (d) 2.0. 108. The insulation resistance of a cable of length 10 km is 1 MΩ, its resistance for 50 km length will be: (a) 1 MΩ (b) 5MΩ (c) 0.2 MΩ (d) None of the above . 109. The capacitance of a 3-core cable between any two conductors with sheath earthed is 2 μF. The capacitance per phase will be: (a) 1 μF (b) 4 μF (c) 0.667 μF (d) 1.414 μF. 110. If δ is the loss angle of the cable, its power factor is: (a) sin δ (b) cos δ (c) Power factor is independent of δ (d) Power factor depends upon δ but it is not as per (a) and (b).