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

Question: The output voltage Vo of the above circuit is____________?

• 1. -6V
• 2. -5V
• 3. -1.2V
• 4. -0.2V

Question: In the above circuit the current ix is___________?

• 1. 0.6A
• 2. 0.5A
• 3. 0.2A
• 4. 1/12A

Question: An opamp has a slew rate of 5V/ S. the largest sine wave o/p voltage possible at a frequency of 1MHz is____________?

• 1. 10 V
• 2. 5 V
• 3. 5V
• 4. 5/2 V

Question: The approximate input impedance of the opamp circuit which has Ri=10k, Rf=100k, RL=10k?

• 1. ∞
• 2. 120k
• 3. 110k
• 4. 10k

Question: An amplifier using an opamp with slew rate SR=1v/sec has a gain of 40db.If this amplifier has to faithfully amplify sinusoidal signals from dc to 20KHz without introducing any slew-rate induced distortion, then the input signal level exceed_____________?

• 1. 795mV
• 2. 395mV
• 3. 795mV
• 4. 39.5mV