# Electrical Measurements Questions and Answers – CRO Measurements

This set of Electrical Measurements & Measuring Instruments Multiple Choice Questions & Answers (MCQs) focuses on “CRO Measurements”.

1. By making use of a CRO _________
a) many characteristics of a signal can be measured
b) only a few characteristics of a signal can be measured
c) no characteristics of a signal can be measured
d) signal can only be displayed

Explanation: Through the means of a Cathode Ray Oscilloscope, most of the characteristics of an input signal can be measured. Properties of a signal can be studied as well.

2. How is the waveform adjusted?
b) through shift controls
c) by reducing the current
d) by means of a galvanometer

Explanation: In a Cathode Ray Oscilloscope, the waveform can be adjusted by means of shift controls. As a result, the measurement of divisions corresponding to the amplitude becomes easy.

3. How is error in measurement reduced?
a) using r.m.s value
b) using absolute value
c) using peak to peak value
d) using a voltmeter

Explanation: In a Cathode Ray Oscilloscope, the error in measurement is reduced by making use of the peak to peak value.

4. Peak to peak voltage is given by ________
a) Vp-p = number of units × $$(\frac{1}{division})$$
b) Vp-p = $$(\frac{volts}{division})$$
c) Vp-p = number of units × volts
d) Vp-p = number of units × $$(\frac{volts}{division})$$

Explanation: In a Cathode Ray Oscilloscope, the peak to peak voltage is given by the relation,
Vp-p = number of units × $$(\frac{volts}{division})$$
where, Vp-p is the peak to peak voltage.

5. The amplitude of voltage is given by which of the following relation?
a) Vm = $$\frac{V_{p-p}}{2}$$
b) Vm = $$\frac{V_{p-p}}{4}$$
c) Vm = 2 × Vp-p
d) Vm = 4 × Vp-p

Explanation: In a Cathode Ray Oscilloscope, the amplitude of voltage is given by the relation,
Vm = $$\frac{V_{p-p}}{2}$$
where, Vp-p is the peak to peak voltage
Vm is the amplitude.

6. The R.M.S voltage is given by which of the following relation?
a) Vrms = $$\frac{V_m}{2}$$
b) Vrms = $$\frac{V_m}{\sqrt{2}}$$
c) Vrms = $$\frac{V_m}{8}$$
d) Vrms = $$\frac{V_m}{\sqrt{8}}$$

Explanation: The r.m.s value of voltage is given by the relation,
Vrms = $$\frac{V_m}{\sqrt{2}}$$
where, Vrms is the r.m.s value of voltage
Vm is the amplitude of the voltage.

7. CRO is voltage measuring device.
a) True
b) False

Explanation: Generally, a CRO is a voltage measuring device. Current is measured by passing current through a known value of resistance. Voltage across the resistance is displayed on the screen of the CRO.

8. Period of a waveform is obtained by which of the following relation?
a) T = number of divisions occupied by 1 cycle×(time)
b) T = number of divisions occupied by 1 cycle×(1division)
c) T = number of divisions occupied by 1 cycle×(timedivision)
d) T = number of divisions occupied by 1 cycle

Explanation: The time period of a waveform is obtained by using the relation,
T=number of divisions occupied by 1 cycle×(timedivision).

9. How is frequency related to time period?
a) square proportional
b) not related
c) directly proportional
d) inversely proportional

Explanation: Frequency is inversely proportional to the time period of any given signal.
f = 1t
where, f is the frequency
T is the time period.

Sanfoundry Global Education & Learning Series – Electrical Measurements.