CL wadhwa bits solutions (53-58)

Lesson 10 of 21 • 48 upvotes • 8:29mins

Anvesh Sameer

53. An overhead line with surge impedance 400 ohms is terminated through a resistance R. A surge travelling over the line does not suffer any reflection at the junction if the value of R is: (a) 20 ohms (b) 200 ohms (c) 800 ohms (d) None of the above.
     54. The rate of rise of restriking voltage depends upon: (a) The type of circuit breaker (b) The inductance of the system only (c) The capacitance of the system only (d) The inductance and capacitance of the system. 55. Gas turbines can be brought to the bus bar from cold in about: (a) 2 minutes (b) 30 minutes (c) 1 Hour (d) 2 Hours. 56. A 3-phase breaker is rated at 2000 MVA, 33 kV, its making current will be: (a) 35 kA (b) 49 kA (c) 70 kA (d) 89 kA. 57. If a combination of HRC fuse and circuit breaker is used, the C.B. operates for: (a) Low overload currents (b) Short circuit current (c) Under all abnormal current (d) The combination is never used in practice. 58. The impulse ratio of a gap of given geometry and dimension is: (a) Greater with solid than with air dielectric (b) Greater with air than with solid dielectric