Quiz Questions - ITI Quiz -

Question 1 1 Marks

Which material is used to make photo resistors (LDR)?

A

Silicon

B

Germanium

C

Aluminium

D

Cadmium sulfide

Question 2 1 Marks

Which is the combination of photo transistor?

A

LASER diode and pin diode

B

Photo transistor and DIAC

C

Photo diode and transistor

D

Photo resistor and TRIAC

Question 3 1 Marks

How the light sensitive photo transistor enclosed inside a tight package is activated?

A

By the bias voltage to the photo transistor

B

By the external signal to the transistor

C

By IR light produced inside the package

D

By the light sensitive receiver inside

Question 4 1 Marks

Which material is used to make LDR for lower end requirements?

A

Aluminium sulfide

B

Cadmium sulfide

C

Zinc sulfide

D

Copper sulfide

Question 5 1 Marks

What is the forward voltage drop of single colour Red LED?

A

1.8 V

B

2 V

C

2.1 V

D

2.2 V

Question 6 1 Marks

What is the maximum reverse voltage that can be applied across the general purpose LED?

A

8 V

B

12 V

C

15 V

D

32 V

Question 7 1 Marks

What is the main application of photo resistor?

A

Voltage rectification

B

Demodulation purpose

C

Controls of street lighting systems

D

To generate oscillations

Question 8 1 Marks

Which material is used to make LDR for higher end requirements?

A

Cadmium sulfide

B

Lead selenide

C

Zinc sulfide

D

Copper sulfide

Question 9 1 Marks

What is the minimum forward current If for single colour LEDs?

A

5 MA

B

10 MA

C

20 MA

D

30 MA

Question 10 1 Marks

What is the type of transistor BPX81?

A

Uni - Junction transistor

B

NPN - Photo transistor

C

PNP - Photo transistor

D

Audio frequency transistor

Question 11 1 Marks

What is the typical forward voltage drop of the RED colour LED?

A

1.8 V

B

2 V

C

2.1 V

D

2.2 V

Question 12 1 Marks

What is the typical forward voltage drop of the yellow colour LED?

A

2.2 V

B

2.1 V

C

2 V

D

1.8 V

Question 13 1 Marks

What is the forward voltage for the single colour orange LEDs?

A

0.5 V

B

0.8 V

C

2 V

D

2.5 V

Question 14 1 Marks

What is the advantage of photo transistors over photo diodes?

A

Considerably lower sensitivity

B

Limit voltage handling capacity

C

Considerable greater sensitivity

D

Vulnerable to electrical sources

Question 15 1 Marks

What is the range of photo current for photo transistor BPX 38?

A

0.1MA to 1.2MA

B

0.2MA to 1.6MA

C

0.3MA to 2.7MA

D

0.4MA to 3.8MA

Question 16 1 Marks

Which circuit uses photo-darlington devices?

A

DC circuits

B

Counter circuits

C

Amplifier circuits

D

AC powered circuits

Question 17 1 Marks

Which measuring instrument is used to check the working condition of a photo resistor (LDR)?

A

Oscilloscope

B

Voltmeter

C

Ohmmeter

D

Ammeter

Question 18 1 Marks

What will happen if the photo resistor (LDR) is exposed to low level light condition?

A

Resistance will decrease to 10 Ohm

B

Resistance will decrease to 100 Ohm

C

Resistance will increase to 1 Kilo Ohm

D

Resistance will increase to around 1 Mega Ohm

Question 19 1 Marks

Which electronic device inversely changes its resistance with the amount of light falling on it?

A

Photo diodes

B

Photo resistors

C

Photo transistors

D

Photo voltaic cells

Question 20 1 Marks

What is the function of opto-coupler in the switching operation of digital input signal?

A

Amplifier the signal

B

Converts voltage into current

C

Produces electrical noise signal

D

Defects the operation of switching signal

Question 21 1 Marks

What is the advantage of PIN photo diodes?

A

Low sensitivity in the infrared range

B

High sensitivity in the infrared range

C

Medium sensitivity in the infrared range

D

Low sensitivity in the Ultraviolet range

Question 22 1 Marks

Which purpose the cadmium sulfide cells (CDS cells) are used?

A

Primary cells

B

Rechargeable cells

C

Light dependent resistor

D

Voltage dependent resistor

Question 23 1 Marks

What is the use of photo transistor?

A

Used in comparator circuit

B

Used as light controlled switch

C

Used as oscillator

D

Used as demodulator

Question 24 1 Marks

Which circuit photo SCR opto couplers are used?

A

DC circuits

B

AC powered circuits

C

Amplifier circuits

D

Counter circuits

Question 25 1 Marks

Which of the device is opto-coupled TRIACS?

A

BT136

B

B3202

C

2N2648

D

MOC3020

Question 26 1 Marks

What is the drawbacks of LDR?

A

More sensitive

B

Available different sizes and specifications

C

Cannot be used to determine precise light levels

D

Made of low resistance material with few holes