Question: A differential amplifier is invariably used in the i/p stage of all op-amps. This is done basically to provide the op-amps with a very high______________?

• 1. CMMR
• 2. Bandwidth
• 3. Slew rate
• 4. Open-loop gain

Question: Assume that the op-amp of the fig. is ideal. If Vi is a triangular wave, then V0 will be______________?

• 1. Square wave
• 2. Triangular wave
• 3. Parabolic wave
• 4. Sine wave

Question: A differential amplifier has a differential gain of 20,000. CMMR=80dB. The common mode gain is given by_______________?

• 1. 2
• 2. 1
• 3. 1/2
• 4. 0

Question: Which of the following amplifier is used in a digital to analog converter?

• 1. Non inverter
• 2. Voltage follower
• 3. Summer
• 4. Difference amplifier

Question: When a step-input is given to an op-amp integrator, the output will be______________?

• 1. A ramp
• 2. A sinusoidal wave
• 3. A rectangular wave
• 4. A triangular wave with dc bias

Question: For an ideal op-amp, which of the following is true?

• 1. The differential voltage across the input terminals is zero
• 2. The current into the input terminals is zero
• 3. The current from output terminal is zero
• 4. The output resistance is zero

Question: In the differential voltage gain & the common mode voltage gain of a differential amplifier are 48db & 2db respectively, then its common mode rejection ratio is________________?

• 1. 23dB
• 2. 25dB
• 3. 46dB
• 4. 50dB

Question: Differential amplifiers are used in______________?

• 1. Instrumentation amplifiers
• 2. Voltage followers
• 3. Voltage regulators
• 4. Buffers

Question: The two input terminals of an opamp are labeled as______________?

• 1. High and low
• 2. Positive and negative
• 3. Inverting and non inverting
• 4. Differential ans non differential

Question: Hysteresis is desirable in Schmitt-trigger, because______________?

• 1. Energy is to be stored/discharged in parasitic capacitances
• 2. Effects of temperature would be compensated
• 3. Devices in the circuit should be allowed time for saturation and desaturation
• 4. It would prevent noise from causing false triggering