GATE EC Analog Circuits questions

For an

n

-channel enhancement type MOSFET, if the source is connected at a higher potential than that of the bulk (i.e.

V_{SB}>0

), the threshold voltage

V_T

of the MOSFET will

Choose the correct match for input resistance of various amplifier configurations shown below

\begin{array}{ll}\text{ Configuration } & \text{ Input resistance } \\ \text{ CB: Common Base } & \text{ LO: Low } \\ \text{ CC : Common Collector } & \text{ MO: Moderate } \\ \text{ CE : Common Emitter } & \text{ HI : High }\end{array}

The circuit shown in the figure is best described as a

If the input to the ideal comparator shown in the figure is a sinusoidal signal of

8 \mathrm{~V}

(peak to peak) without any DC component, then the output of the comparator has a duty cycle of

If the differential voltage gain and the common mode voltage gain of a differential amplifier are

48 \mathrm{~dB}

and

2 \mathrm{~dB}

respectively, then its common mode rejection ratio is

Generally, the gain of a transistor amplifier falls at high frequencies due to the

At

300 \mathrm{~K}

, for a diode current of

1 \mathrm{~mA}

, a certain germanium diode requires a forward bias of

0.1435 \mathrm{~V}

, whereas a certain silicon diode requires a forward bias of

0.178 \mathrm{~V}

. Under the conditions stated above, the closest approximation of the ratio of reverse saturation current in germanium diode to that in …

When the gate-to-source voltage

\left(\mathrm{V}_{\mathrm{GS}}\right)

of a MOSFET with threshold voltage of

400 \; \mathrm{mV}

, working in saturation is

900 \; \mathrm{mV}

, the drain current is observed to be

1 \mathrm{~mA}

. Neglecting the channel width modulation effect and assuming that the MOSFET is operating at saturation, the drain …

An amplifier without feedback has a voltage gain of

50

, input resistance of

1 \mathrm{~K} \Omega

and output resistance of

2.5 \mathrm{~K} \Omega

. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of

0.2

is

In the amplifier circuit shown in the figure is the values of

R_{1}

and

R_{2}

are such that the transistor is operating at

\mathrm{V}_{\mathrm{CE}}=3 \mathrm{~V}

and

\mathrm{I}_{\mathrm{C}}=1.5 \mathrm{~mA}

when its

\beta

is

150.

For a transistor with

\beta

of

200,

the operating point …

The oscillator circuit shown in the figure is has an ideal inverting amplifier. Its frequency of oscillation (in

\mathrm{Hz}

) is

The output voltage of the regulated power supply shown in the figure is

If the

\text{op-amp}

in the figure is idea, the output voltage Voult will be equal to

Three identical amplifiers with each one having a voltage gain of

50,

input resistance of

1 \mathrm{~K} \Omega

and output resistance of

250 \; \Omega

, are cascaded. The open circuit voltage gain of the combined amplifier is

The circuit shown in the figure is a

4

bit

\text{DAC}

The input bits

0

and

1

are represented by

0

and

5 \mathrm{~V}

respectively. The

\text{OP AMP}

is ideal, but all the resistances and the

5 \mathrm{~V}

inputs have a tolerance of

\pm 10 \%

. The specification (rounded to the nearest multiple of

5 \%

) for the tolerance …

If the transistor in the figure is in saturation, then

A

741

-type opamp has a gain-bandwidth product of

1 \; \mathrm{MHz}

. A non-inverting amplifier using this opamp and having a voltage gain of

20 \mathrm{~dB}

will exhibit a

-3-\mathrm{dB}

bandwidth of

In a negative feedback amplifier using voltage-series (i.e. voltage-sampling, series mixing) feedback. (

R_i

and

R_o

denote the input and output resistances respectively)

In given figure a silicon diode is carrying a constant current of

1 \mathrm{~mA}

. When the temperature of the diode is

20^{\circ} \mathrm{C}, \mathrm{V}_{\mathrm{D}}

is found to be

700 \; \mathrm{mV}

. If the temperature rises to

40^{\circ} \mathrm{C}, \mathrm{V}_{\mathrm{D}}

becomes approximately equal to

Consider the following statements in connection with the CMOS inverter in the figure is where both the MOSFETs are of enhancement type and both have a thresh old voltage of

2 \mathrm{~V}

. Statement 1:

\mathrm{T}_{1}

conducts when

\mathrm{V} i \geq 2 \mathrm{~V}

. Statement 2:

T_{1}

is always in saturation when

\mathrm{V}_{0}=0 \mathrm{~V}

. …