MGVCL Exam Paper (30-07-2021 Shift 1) નીચે પૈકી 'અચરજ'નો પર્યાયી શબ્દ ક્યો છે? શાશ્વત જગત વિસ્મય રજ શાશ્વત જગત વિસ્મય રજ ANSWER DOWNLOAD EXAMIANS APP
MGVCL Exam Paper (30-07-2021 Shift 1) Two-wattmeter method is used to measure the power taken by a 3-phase induction motor on no load. The wattmeter readings are 375 W and –50 W. Calculate the reactive power taken by the load. 325√3 VAR 425/√3 VAR 425√3 VAR 325/√3 VAR 325√3 VAR 425/√3 VAR 425√3 VAR 325/√3 VAR ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Reactive power taken, Q = √3*(W1 - W2)Q = √3*(375 + 50)Q = √3*425 kVAR
MGVCL Exam Paper (30-07-2021 Shift 1) 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 aiding. 730 mH 1135 mH 1270 mH 932 mH 730 mH 1135 mH 1270 mH 932 mH ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Mutual inductance (M) = k*√(L1*L2)k = 0.45M = 0.45*√(900*100*10⁻⁶) = 135 mHLeq = L1 + L2 + 2MLeq = 900 + 100 + 270Leq = 1270 mH
MGVCL Exam Paper (30-07-2021 Shift 1) Calculate the capacitance per meter of a 50 Ω load cable that has an inductance of 50 nH/m. 40 pF 30 pF 20 pF 10 pF 40 pF 30 pF 20 pF 10 pF ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Z = √(L/C)C = L/Z²C = 50*10⁻⁹/(50*50)C = 0.02 nFC = 20 pF
MGVCL Exam Paper (30-07-2021 Shift 1) A fully controlled natural commutated 3-phase bridge rectifier is operating with a firing angle α = 30°, The peak to peak voltage ripple expressed as a ratio of the peak output dc voltage at the output of the converter bridge is √3 -1 1-(√3/2) √3-1 0.5 √3 -1 1-(√3/2) √3-1 0.5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Where,φ is firing angleVoltage ripple for 3-phase bridge rectifier = cos(φ) = Cos(30)= 1/2
MGVCL Exam Paper (30-07-2021 Shift 1) By inserting a plate of dielectric material between the plates of a parallel plate capacitor at constant potential, the energy stored in the capacitor is increased five times. The dielectric constant of the material is 1/5 5 25 1/25 1/5 5 25 1/25 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Energy stored by capacitor, Q = ½CV²Dielectric constant is directly proportional to C and capacitance is proportional to the dielectrical constant
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