## 06 June 2012

### Basic Electronics - Quiz

1. The maximum efficiency of a class A amplifier is __________
a) 25%     b) 50%        c) 79%         d) 98%

2. Cross over distortion is a problem for _________ amplifiers.
a) Class A      b) Class AB     c) Class B       d) all the above

3. The band width of an amplifier is determined by the cut-off frequencies. Is it true or false?

4. Push-pull amplifier circuit must use _________ operation.
a) Class A      b) Class B     c) Class C       d) Class AB

5. An ideal op-amp has __________
a) infinite voltage gain    b) infinite i/p impedance   c) zero i/p impedance
d) all the above

6. In superhetrodyne radio receiver, the intermediate frequency for FM wave is
a) 256 khz         b) 455 khz            c) 10.7 Mhz          d) 10.7 khz

7. In amplitude modulation, the carrier power is 100 W. The modulation index is 100%. Then, the power of the A.M. wave is _________
a) 100 W            b) 200 W               c) 150W                d) 1 W

8. Amplitude modulation is basically _________ of two signals.
a) summing     b) multiplication    c) subtraction      d) a non-linear process

9. The total power of an FM wave is not changed due to modulation. Is it true or false?

10. A 555 timer can be used as a voltage controlled oscillator. Is it true or false?

11. The maximum and minimum amplitudes of AM wave are 15 V and 5 V respectively. Then, the modulation index is
a) 0.5                b) 2             c) 75            d) 3

12. The amplitude of the side band in an A.M wave is
a) independent of carrier amplitude   b) independent of modulation index
c) (1/2) x carrier amplitude x modulation index
d) carrier amplitude x modulation index

13. An amplifier that operates in the linear region at all times in _________
a) Class A      b) Class B     c) Class C       d) Class AB

14. For an op-amp with negative feedback, the output is __________
a) equal to the input                                    b) increased
c) feedback to the inverting input   d) feedback to the non-inverting input

15. When the by-pass capacitor in the emitter circuits of a CE transistor amplifier is removed, the gain of the amplifier is increased. Is it true or false.

 Answer Key – Basic Electronics – Quiz 1 25% 2 Class B 3 True 4 Class B 5 all the above 6 10.7 Mhz 7 150W 8 multiplication 9 True 10 True 11 0.5 12 (1/2) x carrier amplitude x modulation index 13 Class A 14 feedback to the inverting input 15 false