MCQs

Keeping all other factors the same, if span length is doubled the sag of the transmission line will: Half Double Triple Quadruple Correct answer: 4. Quadruple Keeping all other factors the same, if span length is doubled the sag of the transmission line will quadruple. Formula for sag is: Sag = wl2/8T Keeping other factors … Read more

Which of the following is a desirable feature in a transistor amplifier: Low input impedance, Low output impedance Low input impedance, High output impedance High input impedance, Low output impedance High input impedance, High output impedance Correct answer: 2. Low input impedance, High output impedance Explanation: The transistor amplifier should have low input impedance and … Read more

Which of the following is the most commonly used transistor arrangement: Common base Common emitter Common collector All of above are equally common Correct answer: 2. Common emitter The common emitter application has highest amount of voltage gain and is most commonly used configuration.

MCQ#1 A 30 HP, 6 pole, 60 Hz slip ring induction motor runs at 940 RPM at full load. The mechanical losses are around 2000 W, while the copper losses in short-circuiting gear are 200 W. The total mechanical output of the motor is: 22380 W 24580 W 48750 W 52500 W Correct answer: 2. … Read more

In Squirrel cage induction motor, the maximum torque developed under running condition is In Squirrel cage induction motor, the maximum torque developed under running condition is: Equal to full load torque Equal to starting torque Higher than full load torque Less than starting torque Correct answer: 3. Higher than full load torque

The armature reaction in alternator influences which of the following factor: Operating speed Windage losses Generated voltage/phase None of these Correct answer: 3. Generated voltage/phase

The losses in an alternator are same as in: Rectifier Transformer DC Generator None of the above Correct answer: 3. DC Generator Like a DC generator, the alternator has a field winding and an armature winding. In both cases (dc generator and alternator) the field excitation is d.c. while emf induced in the armature is … Read more

Which of the following term is not associated with synchronous motor: Doubly fed Constant speed Single fed Variable PF motor Correct answer: 3. Single fed Explanation: A synchronous motor is a doubly-fed variable PF motor, that runs at constant synchronous speed. The term single fed means we are providing only a single supply and no … Read more