RATING AND SERVICE CAPACITY

Objective Questions Short notes Objective questions (Answers are given below) Heat dissipation is assumed proportional to(a) Temperature difference(b) Temperature difference between motorand cooling medium(c) Temperature of cooling medium Temperature of cooling medium is assumed(a) constant (b) variable When the motor reaches final temperature riseits temperature remains(a) constant(b) falls(c) rises. For intermittent load, a motor of … Read more

SINUSOIDAL AND NONSINUSOIDAL OSCILLATORS

Objective Questions Short notes Objective questions (Answers are given below) An electronic oscillator is(a) just like an alternator(b) nothing but an amplifier(c) an amplifier with feedback(d) a converter of ac to dc energy. The frequency of oscillation of an elementaryLC oscillatory circuit depends on(a) coil resistance(b) coil inductance(c) capacitance(d) both (b) and (c). For sustaining … Read more

BREAKDOWN DEVICES

Objective Questions Short notes Objective questions (Answers are given below) A unijunction transistor has(a) anode, cathode and a gate(b) two bases and one emitter(c) two anodes and one gate(d) anode, cathode and two gates. Which semiconductor device acts like a diodeand two resistors ?(a) SCR (b) triac(c) diac (d) UJT. A UJT has RBB = … Read more

FIELD EFFECT TRANSISTORS

Objective Questions Short notes Objective questions (Answers are given below) A FET consists of a(a) source (b) drain(c) gate (d) all of the above. FETs have similar properties to(a) PNP transistors(b) NPN transistors(c) thermonic valves(d) unijunction transistors. For small values of drain-to-source voltage,JFET behaves like a(a) resistor(b) constant-current source(c) constant-voltage source(d) negative resistance In a … Read more

FEEDBACK AMPLIFIER

Objective Questions Short notes Objective questions (Answers are given below) The advantage of using negative feedback in anamplifier is that its gain can be made practicallyindependent of(a) temperature changes(b) age of components(c) frequency(d) all of the above Feedback in an amplifier always helps to(a) control its output(b) increase its gain(c) decrease its input impedance(d) stabilize … Read more