MGVCL Exam Paper (30-07-2021 Shift 3) The current in the coil of a large electromagnet falls from 6 A to 2 A in 10 ms. The induced emf across the coil is 100 V. Find the self-inductance of the coil. 0.5 H 1.25 H 0.25 H 0.75 H 0.5 H 1.25 H 0.25 H 0.75 H ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Equation of self inductance:V = Ls*(di/dt)Ls = V/(di/dt)= 100/((6 - 2)/(0.01))= 0.250 H= 250 mH
MGVCL Exam Paper (30-07-2021 Shift 3) A three phase four pole 50 Hz induction motor has a rotor resistance of 0.02 Ω/phase and stand-still reactance of 0.5 Ω/phase. Calculate the speed at which the maximum torque is developed. 1525 rpm 1500 rpm 1440 rpm 1475 rpm 1525 rpm 1500 rpm 1440 rpm 1475 rpm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Condition for maximum torque,Sm = R2/X2= 0.04Ns = (120*f)/P= (120*50)/4= 1500 rpmS = (Ns - Nr)/NsNr = Ns(1 - Sm)= 1500*(1 - 0.04)= 1440 rpm
MGVCL Exam Paper (30-07-2021 Shift 3) The threshold voltage of an N-channel enhancement mode MOSFET is 0.5 V. When the device is biased at a gate voltage of 3 V, pinch-off would occur at a drain voltage of 4.5 V 1.5 V 2.5 V 3.5 V 4.5 V 1.5 V 2.5 V 3.5 V ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Equation is given by:Vds = Vgs - VtVds = 3 - 0.5Vds = 2.5 V
MGVCL Exam Paper (30-07-2021 Shift 3) Which is the function of Operating System? Devices Management Security All of these Process Management Devices Management Security All of these Process Management ANSWER DOWNLOAD EXAMIANS APP
MGVCL Exam Paper (30-07-2021 Shift 3) નીચે પૈકી કેટલી કહેવતો વિરુદ્ધાથીઁ છે?.1. પાંચ બોલે તે પરમેશ્વર - ગામને મોઢે ગળણું ન બંધાય.2. ચોરની ચાર અને જોનારની બે - વિશ્વાસે વહાણ ચાલે.3. ખાલી ચણો વાગે ઘણો - અધુરો ઘડો છલકાય.4. હાથના કર્યા હૈયે વાગ્યા - દીવો લઈને કૂવામાં પડવું બધી કહેવતો સમાનર્થી છે કુલ 1 એક પણ નહિ કુલ 3 બધી કહેવતો સમાનર્થી છે કુલ 1 એક પણ નહિ કુલ 3 ANSWER DOWNLOAD EXAMIANS APP
MGVCL Exam Paper (30-07-2021 Shift 3) A 10-pole induction motor is supplied by a 6-pole alternator, which is driven at 1400 rpm. If the motor runs with a slip of 5%, what is its speed? 798 rpm 882 rpm 1425 rpm 1575 rpm 798 rpm 882 rpm 1425 rpm 1575 rpm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Slip of the induction motor,S = (Ns - Nr)/NsNs = (120*f)/PPoles (P) = 61400 = (120*f)/6f = 70 HzFor P = 10Ns = (120*70)/10= 840 rpmNr = Ns(1 - S)= 840*(1 - 0.05)= 798 rpm
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