Which of the following statements are correct?

(A) An Instrumentation Amplifier must have low dc offset as well as low output impedance.

(B) A Voltage to current converter is used for LED and Zener diode testing.

(C) Current to voltage converter is also called transconductance amplifier.

(D) A Sample and hold circuit is used in digital to analog interfacing.

(E) A precision diode may never be used as peak value detector.

Choose the correct answer from the options given below:

Question

Question

This question was previously asked in

UGC NET Paper 2: Electronic Science 29 Oct 2022 Shift 1

Answer 1

The correct answer is option 1.

Instrumentation amplifiers

Instrumentation amplifiers are precision, integrated operational amplifiers that have differential input and single-ended or differential output.
Some of their key features include a very high common mode rejection ratio (CMRR), high open loop gain, low DC offset, low drift, high input impedance, low output impedance, and low noise. Hence, statement A is true.

Voltage to current converter

These are also known as the transconductance amplifier.
Floating load V to I converters are used as low voltage ac and dc voltmeters, diode, LED, and zener diode testers. Hence, statement B is true.

Current to voltage converter

These are also known as the trans resistance amplifier. Hence, statement C is false.

Sample and hold circuit

It is not used for analog to digital conversion.
It just samples (captures, takes) the voltage of a continuously varying analog signal and holds (locks, freezes) its value at a constant level for a specified minimum period of time.
These are essential for minimizing voltage skew errors during the analog-to-digital conversion process as they hold the input voltage to the ADC constant during the conversion. Hence, statement D is false.

Precision Rectifier

The precision rectifier has the capability of rectifying voltages that are of a smaller magnitude than the forward voltage drop.
The precision rectifier can be used as a peak detector by connecting capacitance at the output.
In this case, it will charge to the peak value in a positive cycle and hold the peak value in a negative cycle hence acting like a peak detector. Hence, statement E is false.