CL wadhwa bits solutions (22-28)

Lesson 5 of 21 • 53 upvotes • 13:35mins

Anvesh Sameer

22. For a long transmission line, for a particular receiving end voltage, when sending end voltage is calculated, it is more than the actual value when calculated by: (a) Load end capacitance method (b) Nominal T method (c) Nominal π method (d) None of the above methods. 23. The p.u. impedance value of an alternator corresponding to base values 13.2 kV and 30 MVA is 0.2 p.u. The p.u. value for the base values 13.8 kV and 50 MVA will be: (a) 0.306 p.u. (b) 0.33 p.u. (c) 0.318 p.u. (d) 0.328 p.u. 24. For the same rupturing capacity, the actual current to be interrupted by an HRC fuse is: (a) Much less than any CB (b) Much more than any CB (c) Equal to the CB (d) None of the above is necessary. 25. The stability of arc in vacuum depends upon: (a) The contact material only (b) The contact material and its vapour pressure (c) The circuit parameters only (d) The combination of (b) and (c). 26. To limit current chopping in vacuum circuit breakers, the contact material used has: (a) High vapour pressure and low conductivity properties (b) High vapour pressure and high conductivity properties (c) Low vapour pressure and high conductivity properties (d) Low vapour pressure and low conductivity properties. 27. The capacitor switching is easily done with: (a) Air blast circuit breaker (b) Oil C.B. (c) Vacuum C.B. (d) Any one of the above. 28. Where voltages are high and current to be interrupted is low the breaker preferred is: (a) Air blast C.B. (b) Oil C.B. (c) Vacuum C.B. (d) Any one of the above.