Selecting the Correct CRO Probe
The goal is to measure a 250V DC voltage using a Cathode Ray Oscilloscope (CRO) which has a maximum input voltage limit of 30V. We need to find the lowest probe attenuation factor that safely brings the measurement within the CRO's limit.
Probe Attenuation Explained
Probes with an attenuation factor (like 1X, 10X) reduce the voltage reaching the CRO input. A probe marked 'NX' reduces the voltage by a factor of N. The voltage displayed on the CRO will be the actual voltage divided by the probe factor.
Calculating Required Attenuation
The maximum voltage the CRO can safely handle is 30V. The actual voltage to be measured is 250V DC.
- 1X Probe: Displays \(250V \div 1 = 250V\). This exceeds the 30V limit.
- 10X Probe: Displays \(250V \div 10 = 25V\). This is within the 30V limit.
- 100X Probe: Displays \(250V \div 100 = 2.5V\). This is within the 30V limit.
- 1000X Probe: Displays \(250V \div 1000 = 0.25V\). This is within the 30V limit.
Determining the Lowest Suitable Probe
The probes that allow measurement within the CRO's limit are 10X, 100X, and 1000X. The question asks for the lowest scale probe suitable. Comparing the suitable options (10X, 100X, 1000X), the lowest attenuation factor is 10X.
Therefore, the lowest scale probe suitable for measuring 250V DC using a CRO with an input limit of 30V is the 10X probe.
Similar Questions
A CRO displays a sine waveform which spans 3 cycles in 6 horizontal divisions. If the time base switch is set to 1 ms/div, what is the frequency of this signal which is being measured?
- The shape of the time base signal of a CRO is generally a _____.
CRO stands for:
- How is a Lissajous pattern created?
Aquadag coating is most commonly used in CROs to:
- What cannot be measured using a CRO device?
Important Questions from Cathode Ray Oscilloscope
Calculate the maximum velocity of the beam of electrons in a CRT having a cathode and anode voltage of 182 V. Assume that the electrons leave the cathode with zero velocity. (Charge of electron = 1.6 × 10-19 C and mass of electron = 9.1 × 10-31 kg)
Which of the following expression is the correct formulae for the deflection sensitivity ‘S’ of a CRT, if
D = deflection on the fluorescent screen
L = distance from the center of the deflection plates to the screen
Ld = effective length of the deflection plates
d = distances between the deflection plates
Ed = Potential between deflecting plates
Ea = accelerating voltageTrigger pulses in CRO are used -
- A Lissajous pattern obtained on a CRO screen is a straight line. The frequencies of the two signals are
Which element in CRO is used to collect secondary emission electrons?
