Basic Electronics mcqs paper 1
1. Voltage across 4 ohm resistance in respect of the following drawing circuit
will be
a) 12 V b) 6 V
c) 4 V d) 20 V
Electric Transformer Theory
Any two coils magnetically linked will act as transformers. Transformers come in as many forms as inductors, air or dust cored as well as the more familiar iron-cored type. The iron-core can take several forms.
The simple transformer comprises two or more inductors (windings) sharing a common core. See Power Supplies for an explanation.
An alternating current is fed to one of the windings. The operation can explained by considering the magnetic field of the input winding, the primary, sweeping through the secondary winding to induce an AC current in the secondary. These principles are considered in AC
The "turns ratio"
A common task for a transformer is to provide an AC supply at a voltage suitable for rectifying to produce a stated DC output.
Inductors Resonance
We'll start with the inductor!
The Inductor
This figure shows a conductor carrying a current. A magnetic field is set up around the conductor as concentric circles.
If a coil of wire has a current flowing through it, the magnetic flux due to each turn will link with every other turn and produce the same sort of magnetic field as a permanent magnet. Such a coil is called a solenoid as shown here. It acts as a magnet only when current is flowing through it.
The magnetic polarity of the solenoid can be determined from the 
direction of current flow as seen looking in the ends, as shown in the diagram. From that the direction in which the magnetic field is acting can also be found.
Solenoids or electromagnets are widely used in electronic equipment. Loudspeakers, headphones, moving coil microphones, measuring instruments, transformers and such things, depend on electromagnetism for their operation.
A inductor may be air-cored or have a solid core.
MCQs in Radio Engineering Part – 2 (Electronics and Communication Engineering) Test Paper
Choose the correct answer
1. Medium wave broadcast band is from
a) 530 kHz to 1600 kHz
b) 3 MHz to 10 MHz
c) 10 MHz to 30 MHz
PSU Sample Paper 3
1 Which of the following is not true for common collector amplifier?
a) half b) one third c) two third d) one fourth
2. The power input to a three phase induction motor is 62 kW. The stator loss is 2 kW. If the rotor is running with a slip of 5%, the total copper loss in the rotor will be:
a) 500 W b) 1000 W c) 1500 W d) 3000 W
3. A transformer has an iron loss of 250 W and full-load copper loss of 1000 W. At what percentage of full-load, the efficiency becomes maximum:
PSU Sample Paper 1
Multiple choice Questions
1. The velocity of sound is the least in which of the following medium:
1) Air 2) Water 3) Wood 4) Vacuum
2. Two amplifier stages have voltage gains of 100 and 200. The total decibel voltage gain of the cascaded amplifiers is:
1) 46 dB 2) 86 dB 3) 66 dB 4) 106 dB
3. In the circuit shown, what is the minimum value of RL for which the output voltage will remain constant?
