Electronic instruments MCQs

1.An ammeter with a resistance of G ohms and a maximum current range of I amperes needs to be modified to measure up to n times the original current (nI). What should be the value of the resistance connected in parallel to achieve this new range?

2.What parameters can a Cathode Ray Oscilloscope (CRO) measure?

3.A voltmeter with an internal resistance of G ohms and a voltage range of V volts needs to be modified to measure up to nV volts. What resistance should be connected in series to achieve this new range?

4.Which device among the following typically exhibits the highest electrical resistance?

A voltmeter with a 10 V measurement rangeA moving coil galvanometerAn ammeter designed for 1 A currentA 1-meter long copper wire with a diameter of 3 mm

5.What is the resistance value of a perfect voltmeter?

6.What should be the value of the shunt resistance if a galvanometer with resistance G is to carry only 2% of the total current?

7.Which type of waveform is applied to the horizontal plates of a CRO to display the signal waveform properly?

A sine waveA cosine waveformA sawtooth waveformNo waveform is applied

8.What is the resistance value of an ideal ammeter?

9.What value of shunt resistor is needed to allow only 10% of the total current to pass through a moving coil galvanometer with a resistance of 99 Ω?

11 Ω9 Ω100 Ω9 Ω

10.What happens to the brightness of the spot on a CRT screen when the negative voltage on the control grid is made more negative?

11.Given two multimeters, A and B, with sensitivities of 10 kΩ/V and 30 kΩ/V respectively, which one has higher sensitivity?

Multimeter A exhibits greater sensitivityMultimeter B has higher sensitivityBoth multimeters have the same sensitivityNone of the above options are correctCannot determine from the given data

12.Calculate the overall resistance of a voltmeter set to the 10 V range if the full-scale deflection current of the meter movement is 50 µA.

10 kilo-ohms20 kilo-ohms200 kilo-ohmsNone of these

13.A series ohmmeter is powered by a 3 V battery and includes a meter movement rated at 1 mA. What resistance corresponds to the half-scale deflection of this meter?

14.What happens to the current in a circuit when an ammeter is connected in series?

It risesIt dropsIt stays constantNo change applies

15.Which of the following is a VTVM not designed to measure?

16.Which type of voltage is supplied to the horizontal deflection plates of a CRO to produce a signal pattern on the screen?

17.If a galvanometer with resistance G is connected in parallel with a very low resistance S (shunt), what is the total resistance of the resulting ammeter?

The product of G and S divided by their sum, i.e., (G × S) / (G + S)The sum of G and S, i.e., G + SThe difference between G and S, i.e., G - SNone of these options