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.
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.
The relation between electric intensity E, voltage applied V and the distance d between the plates of a parallel plate condenser is given by: V = E*L E = V/L
Where, d is distance in m Q is value of variable resistor in ohm P is variable resistance in ohm Here Q/P = 1/3 is given, d = Q/(P + Q)*Loop length = 1/4*(2*600) = 300 m
Here, ω = 500 rad/sec = 2πf. At Resonance condition, ωL = 1/(ωC) L 0.2 H Also at series resonace 1. fr = 1/[2π√(LC)] 2. PF = 1 3. Maximum current 4. Source voltage = voltage across resistor.
EXAMIANS