Electronics Instrumentation objective questions:



Q1. The decibel is a measure of

1.    Current
2.    Voltage
3.    Power
4.    Power level
Ans : 4

Q2. Power gain in decibels is equal to voltage gain in decibels only when

1.    Input impedance is equal to output impedance
2.    Output impedance is zero
3.    Never
4.    Input impedance is zero
Ans : 1

Q3.  An ideal amplifier has

   1. Noise figure of 0 db
   2. Noise figure of more than 0 db
   3. Noise factor of unity
   4. Noise figure of less than 1 db
Ans : 3

Q4. Fidelity represents
S1: Reproduction of signal
S2: Reproduction of phase relation

1.  S1 and S2 are true
2.  S1 and S2 are false
3.  S1 false and S2 true
4.  S1 true and S2 false
Ans : 4

Q5. If the current gain of the amplifier is X, its voltage gain is Y, then its power gain will be

1. X/Y
2.  X*Y
3.  X+Y
4.  X-Y
Ans : 2

Q6. In an amplifier, the coupling capacitors are employed for

1.  Limiting the bandwidth
2. Matching the impedance
3. Preventing of Dc mixing with input or output
4. Controlling the output
Ans : 3

Q7. The amplifier which has no drift is called as

1. Differential amplifier
2. DC amplifier
3. Single ended amplifier
4. Chopper amplifier
Ans : 4

Q8. The amplifier gain varies with frequency. This happens mainly due to

1. Miller effect
2. Presence of external and internal capacitance
3. Logarithmic increase in its output
4. Inter stage transformer
Ans : 2

Q9. A voltmeter should have ………. resistance

1.  Zero
2. Very high
3. Very low
4. None of the above

Ans : 2

Q10. For display of signal pattern ………… voltage is applied to the horizontal plates of a CRO
1. Sinusoidal
2. Rectangular
3. Sawtooth
4. None of the above

Ans : 3

Q11. The most accurate device for measuring voltage is ………….

1. Voltmeter
2. Multimeter
3. CRO
4. VTVM

Ans : 3

Q12. A CRO is used to measure ………….

1.  Voltage
2. Frequency
3. Phase
4. All of above

Ans: 4

Q13. An ideal ammeter has ………… resistance

1. Low
2. Infinite
3. Zero
4. High

Ans : 3

Q14. An ammeter should have ………….. resistance 
1. Infinite
2. Very large
3. Very low
4. None of the above

Ans: 3

Q15. CMRR is more in_______________

1. Single ended amplifier
2. Differential amplifier
3. Inverting operational amplifier
4. Chopper amplifier

Ans : 2

Q16. The sensitivity of a multimeter is given in ……………..
1. Ω
2. Amperes
3.  kΩ/V
4. none of the above

Ans : 3

Q17. ___________ amplifier is used to drive the recorder.

1. Power amplifier
2. Pre amplifier
3. Operational amplifier
4. Differential amplifier

Ans : 1

Q18. When a number of components are fabricated on same IC chip it is necessary to provide isolation between two different components for input interconnection is called __________

1. Input amplification
2. Input differentiation
3. Common mode rejection
4. Input isolation

Ans : 4

Q19. A chopper amplifier

1. Converts AC signal from low frequency to high frequency
2. Converts DC signal from low frequency to high frequency
3. Converts AC signal from low frequency to DC high frequency
4. Converts DC signal from low frequency to high frequency

Ans : 2

Q20. Power amplifier is provided with
S1: Cross over distortion compensation
S2: Offset control

1. S1 is true & S2 is false
2. S2 is true & S1 is false
3. Both S1 & S2 are true
4. Both S1 & S2 are false

Ans : 3

Q21. A VTVM is never used to measure …………..
1. Voltage
2.  Current
3. Resistance
4.  None of the above

Ans: 2

Q22. A ————– is usually a display device used to produce a paper record of analog wave form.
1. Graphic pen recorder
2. Electron microscope
3. X-Y recorder
4. Oscilloscope

Ans : 1
 

Q23. Common mode rejection ratio is defined as ratio of

1. Common mode gain to differential mode gain
2. Differential mode gain to common mode gain
3. Common mode gain at input to differential mode gain at input
4. Common mode gain at output to differential mode gain at output

Ans : 2

Q24. When the input of differential amplifier V1 = 0, then the differential amplifier is said to be operated in

1. Common mode
2. Differential mode
3. Non inverting mode
4. Inverting mode

Ans : 3