MGVCL Exam Paper (30-07-2021 Shift 2)
A coil having an inductance of 100 mH is magnetically coupled to another coil having an inductance of 900 mH. The coefficient of coupling between the coils is 0.45. Calculate the equivalent inductance if the two coils are connected in series opposing.
When different types of consumers are charged at different uniform per unit rates, it is said to be Flat Rate Tariff. In this type, the consumers are grouped into different classes. Each class is charged at different uniform rate.
A thermopile is an electronic device that converts thermal energy into electrical energy. It is composed of several thermocouples connected usually in series or less commonly, in parallel. Thermopiles are used for contactless temperature sensing. The function of a thermopile is to transfer the heat radiation emitted from the object to a voltage output. The output is in the range of tens or hundreds of millivolts.
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 neutral point of a generator is usually earthed to facilitate protection of the stator winding and associated system. Earthing also prevents damaging transient overvoltages in the event of an arcing earth fault or ferro resonance. For HV generators, impedance is usually inserted in the stator earthing connection to limit the magnitude of earth fault current.