Operational Amplifiers Op Amps Practice Questions

An opamp has a finite open loop voltage gain of 100. Its input offset voltage $V_{ios}(=+5mV)$ is modeled as shown in the circuit below. The amplifier is ideal in all other respects. $V_{input}$ is 25 mV. The output voltage (in millivolts) is ________

An ideal opamp has voltage sources $V_1, V_3, V_5,..., V_{N-1}$ connected to the non-inverting input and $V_2,V_4, V_6,...,V_{N}$ connected to the inverting input as shown in the figure below (+ $V_{cc}$ = 15 volt,- $V_{cc}$ = -15 volt). The voltages $V_1, V_2, V_3, V_4, V_5, V_6,...$ are 1, -1/2, 1/3, -1/4, 1/5, -1/6,... volt,respectively. As N approaches infinity, the output voltage (in volt) is ___________

In the opamp circuit shown, the Zener diodes Z1 and Z2 clamp the output voltage $V_{o}$ to +5 V or -5 V. The switch S is initially closed and is opened at time t=0. The time t= $t_{1}$ (in seconds) at which $V_{o}$ changes state is ________

In the circuit shown, assume that the opamp is ideal. The bridge output voltage $V_{0}$ (in mV) for $\delta$ = 0.05 is _______.

Assuming that the opamp in the circuit shown below is ideal, the output voltage $V_{o}$ (in volts) is________.

In the circuit shown, $V_{0} = V_{0A}$ for switch SW in position A and $V_{0} = V_{0B}$ for SW in position B. Assume that the opamp is ideal. The value of $\frac{V_{0B}}{V_{0A}}$ is ___________.

In the bistable circuit shown, the ideal opamp has saturation levels of $\pm 5 V$ . The value of $R_{1}$ $(\in \; k\Omega)$ that gives a hysteresis width of 500 mV is ________.

In the circuit shown using an ideal opamp, the 3-dB cut-off frequency (in Hz) is _______.

For the voltage regulator circuit shown, the input voltage ( $V_{\in}$ ) is $20 V \pm 20$ % and the regulated output voltage ( $V_{out}$ ) is 10 V. Assume the opamp to be ideal. For a load $R_{L}$ drawing 200 mA, the maximum power dissipation in $Q_{1}$ (in Watts) is ________.

In the circuit shown, assume that the opamp is ideal. If the gain ( $v_{o} / v_{\in}$ ) is -12, the value of R (in k $\Omega$ ) is _____.

In the differential amplifier shown in the figure, the magnitudes of the commonmode and differential-mode gains are $A_{cm} \; and \; A_{d}$ , respectively. If the resistance $R_{E}$ is increased, then

In the low-pass filter shown in the figure, for a cut-off frequency of 5 kHz, the value of $R_2$ (in K $\Omega$ ) is _____.

Assuming that the Op-amp in the circuit shown is ideal, $V_{0}$ is given by

In the circuit shown, the op-amp has finite input impedance, infinite voltage gain and zero input offset voltage. The output voltage $V_{out}$ is

The circuit shown represents

In the voltage regulator circuit shown in the figure, the op-amp is ideal. The BJT has $V_{BE}=0.7 V$ and $\beta =100$ , and the zener voltage is 4.7 V. For a regulated output of 9V, the value of R (in $\Omega$ ) is _____.

In the circuit shown below what is the output voltage $\left ( V_{out} \right )$ if a silicon transistor Q and an ideal op-amp are used?

In the circuit shown below the op-amps are ideal. Then $V_{out}$ in Volts is

The circuit shown is a