36. Which of the following statement about CRO is correct?
    

1. 1. The lissajous pattern obtained on a CRO is used to measure distortion in the input signal
      

   
   
   

   2. The colour of the spot on the screen of a CRO is a characteristic of the electron gun in a CRT
      

   
   
   

   3. The time base signal in a CRO is a square waveform
      

   
   
   

   4. None of the above

   
   
   

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   NA

   Correct Option: D

   NA

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37. It is desired to measure voltage across of 100 K ohm resistor. Which out of the following four voltmeters will give most reliable results?
    

1. 1. Voltmeter with sensitivity of 5 K ohm/ V
      

   
   
   

   2. Voltmeter with sensitivity of 10 K ohm/ V
      

   
   
   

   3. Voltmeter with sensitivity of 20 K ohm/ V
      

   
   
   

   4. Voltmeter with sensitivity of 50 K ohm/ V

   
   
   

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   Higher the sensitivity of the instrument will give more accurate and reliable result.

   Correct Option: D

   Higher the sensitivity of the instrument will give more accurate and reliable result.

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38. Low resistance is measured by:
    

1. 1. De Sauty’s bridge
      

   
   
   

   2. Maxwell’s bridge
      

   
   
   

   3. Kelvin’s double bridge
      

   
   
   

   4. Wien bridge

   
   
   

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   Low resistance is measured by Kelvin’s double bridge.

   Correct Option: C

   Low resistance is measured by Kelvin’s double bridge.

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39. Ballistic galvanometer can be used to measure:
    

1. 1. Current
      

   
   
   

   2. (a) and (b) both
      

   
   
   

   3. Flux
      

   
   
   

   4. None of these

   
   
   

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   Ballistic galvanometer can be used to measure current as well as flux.

   Correct Option: C

   Ballistic galvanometer can be used to measure current as well as flux.

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40. The measurement of very low and very high frequencies is invariably done using a frequency counter/time in the:
    

1. 1. frequency measurement mode only
      

   
   
   

   2. period measurement mode only
      

   
   
   

   3. frequency and period measurement modes respectively
      

   
   
   

   4. period and frequency measurement modes respectively

   
   
   

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   ● The measurement for very low frequencies is done by period mode.
   ● The measurement for very high frequencies is done by frequency mode.

   Correct Option: D

   ● The measurement for very low frequencies is done by period mode.
   ● The measurement for very high frequencies is done by frequency mode.

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