Chapter: Electronics
1.

LED starts to conduct when voltage is about

A. 1 V
B. 4 V
C. 3 V
D. 2 V
Answer» D. 2 V
2.

For non-inverting amplifier the input and output is

A. out of phase
B. in phase
C. have phase difference of 180°
D. have phase difference of 90°
Answer» B. in phase
3.

A sensing device is also called

A. transistor
B. thermistor
C. sensor
D. transducer
Answer» D. transducer
4.

Op-amp can provide maximum output current of

A. 25 mA
B. 30 mA
C. 35 mA
D. 40 mA
Answer» A. 25 mA
5.

Output resistance of an actual op-amp is

A. 45Ω
B. 46Ω
C. 70Ω
D. 75Ω
Answer» D. 75Ω
6.

Impedance of ideal op-amp is

A. zero
B. 1
C. infinite
D. 2
Answer» C. infinite
7.

Change in length and cross-sectional area of metal wire changes

A. current
B. voltage
C. resistance
D. magnetic effect
Answer» C. resistance
8.

Amplifier produces output with more

A. power only
B. voltage only
C. current only
D. power and voltage
Answer» D. power and voltage
9.

Number of power supplies required to get output of op-amp is

A. two
B. four
C. six
D. three
Answer» A. two
10.

A device used to avoid the relay destroying the op-amp is

A. diode
B. LED
C. reverse bias diode
D. forward biased diode
Answer» C. reverse bias diode
11.

As long as op-amp is not saturated, the potential difference between inverting and non-inverting inputs is

A. zero
B. infinite
C. 1
D. 2
Answer» A. zero
12.

A light dependent resistor is made up of

A. low resistance semiconductor
B. low resistance metal
C. high resistance semiconductor
D. high resistance metal
Answer» C. high resistance semiconductor
13.

In inverting amplifier, the phase difference between input and output voltages must be

A. 30°
B. 45°
C. 90°
D. 180°
Answer» D. 180°
14.

An infinite slew rate refers to

A. no time delay
B. small time delay
C. large time delay
D. variable time delay
Answer» A. no time delay
15.

To limit current in LED, resistor should be connected in

A. parallel
B. series
C. evacuated flask
D. ionized tube
Answer» B. series
16.

A component whose property changes when there is a change in any physical quantity of a device is

A. processor
B. sensor
C. output device
D. portable device
Answer» B. sensor
17.

Benefits of negative feedback include

A. less distortion
B. increased bandwidth
C. low output resistance
D. all of above
Answer» D. all of above
18.

When temperature rises, resistance of negative temperature coefficient thermistor

A. increases
B. decreases
C. zero
D. infinity
Answer» B. decreases
19.

If current of 20 mA is passing through op-amp and voltage drop across series resistor is 10 V then value of resistance is

A. 500Ω
B. 400Ω
C. 300Ω
D. 200Ω
Answer» A. 500Ω
20.

Graph of resistance of thermistor to temperature is

A. exponential decrease
B. linear decrease
C. exponential increase
D. linear increase
Answer» A. exponential decrease
21.

Output current from an LED is

A. 20 mA
B. 30 mA
C. 40 mA
D. 50 mA
Answer» A. 20 mA
22.

In an inverting amplifier the non-inverting input (+) is connected to

A. 1 V line
B. 0 V line
C. 2 V line
D. 3 V line
Answer» B. 0 V line
23.

Actual op-amp may have an open loop gain of{{}}

A. 102
B. 105
C. 103
D. 104
Answer» B. 105
24.

Coil of relay is connected to the

A. input of op-amp
B. output of op-amp
C. midpoint of op-amp
D. anywhere in between input and ouput of op-amp
Answer» B. output of op-amp
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