MGVCL Exam Paper (30-07-2021 Shift 2) A three-phase, 4-pole, 50 Hz induction motor runs at 1425 rpm. Find out the percentage slip of the induction motor. 3% 6% 4% 5% 3% 6% 4% 5% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Slip, s = (Ns - Nr)/NsNs = 120f/PNs = 1500 rpms = (1500 - 1425)/1500s = 0.05%s = 5%
MGVCL Exam Paper (30-07-2021 Shift 2) A 1000 kVA ONAN cooled transformer has a load of 500 kVA throughout the day except for a period of 4 hours. What is the permissible overload for a duration of four hours. Assume the permissible load kVA as a fraction of rated kVA is 1.24. 2480 kVA 930 kVA 1240 kVA 620 kVA 2480 kVA 930 kVA 1240 kVA 620 kVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Permissible overload = Full load kVA*factor for permissible load= 1000*1.24= 1240 kVA
MGVCL Exam Paper (30-07-2021 Shift 2) A generating station having 'n' section busbars each rated at Q kVA with ×% reactance is connected on the tie-bars systems through busbar reactances of b%. Determine the short circuit kVA if a 3-phase fault takes place on one section. Q[(1/x) + (n+1)/(bn-x)] Q[(1/x) + (n-1)/(bn+x)] Q[(1/x) - (n+1)/(bn-x)] Q[(1/x) + (n+1)/(bn+x)] Q[(1/x) + (n+1)/(bn-x)] Q[(1/x) + (n-1)/(bn+x)] Q[(1/x) - (n+1)/(bn-x)] Q[(1/x) + (n+1)/(bn+x)] ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA of any bus is given by:Skva = Sbase*(100/% X)Where,Sbase - base rating in kVA% X - value of reactance in %
MGVCL Exam Paper (30-07-2021 Shift 2) Consider the following statements associated with Buchholz's relays.Statement 1: Buchholz's relay is a current operated device.Statement 2 : Buchholz's relay is placed between the transformer tank and the conservator. Statement 1 is FALSE and Statement 2 is TRUE Statement 1 is TRUE and Statement 2 is FALSE Both Statement 1 and Statement 2 are TRUE Both Statement 1 and Statement 2 are FALSE Statement 1 is FALSE and Statement 2 is TRUE Statement 1 is TRUE and Statement 2 is FALSE Both Statement 1 and Statement 2 are TRUE Both Statement 1 and Statement 2 are FALSE ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Buchholz relay is gas operated relay.It will operate when internal fault occurs in transformer.It is placed between tank to main conservator.It has two contacts trip and alarm.Use of Buchholz relay in distribution transformer is not economical.
MGVCL Exam Paper (30-07-2021 Shift 2) Which one of the following is the largest windfarm located in India? Vindhayachal Mundra Talcher Muppandal Vindhayachal Mundra Talcher Muppandal ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Rank - Windfarm name - Capacity1 - Muppandal windfarm - 1500 MW2 - Jaisalmer Wind Park - 1064 MW3 - Brahmanvel Wind Farm Dhule - 964 MW4 - Damanjodi Wind Farm - 99 MW5 - Tuppadahalli Wind Farm - 56.1 MW
MGVCL Exam Paper (30-07-2021 Shift 2) The wind speed increases with height because of reduction of drag effect of the earth surface reduction in the gravitational force reduction in lift effect of the air enhancement of drag effect on the earth surface reduction of drag effect of the earth surface reduction in the gravitational force reduction in lift effect of the air enhancement of drag effect on the earth surface ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Wind speed increases as the height from the ground increases mainly due to the decrease in the friction produced by land terrain.
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