Directions: Each item consists of two statements, one labeled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Solar insolation is a measure of solar irradiance over a specified period of time.Statement (II): Solar insolation data are commonly used for isolated PV system design.

Statement (I) is true but Statement (II) us false

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement(II) are individually true but Statement (II) is not the correct explanation of Statement(I)

Statement (I) is true but Statement (II) us false

Statement (I) is false but Statement (II) is true

Direction: Question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. Examine these two statements carefully and select the answer to this question using the codes given below:Assertion (A): Many semiconductors where minimum energy in the conduction band and maximum energy in the valence band occur at the same value of \(\mathop k\limits^ \to \) (wave vector), are preferred for optical lenses.Reason (R): For such semiconductors, the efficiency of carrier generation and recombination is very high.

Both A and R are individually true but R is not the correct explanation of A

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is not the correct explanation of A

A PIN diode consists of:

heavily doped p region, lightly doped n region separated by a low resistivity material

heavily doped p region, lightly doped n region separated by a high resistivity material

lightly doped p region, lightly doped n region separated by a low resistivity material

heavily doped p and n regions separated by a high resistivity material

heavily doped p region, lightly doped n region separated by a low resistivity material

Assertion (A): A p-n junction diode with low junction depth can be used as a solar cell when illuminated by suitable light (wavelength) at the top thin layer above the junction.Reason (R): A p-n junction diode under no condition can be used as a solar cell. It can be used only as a light-emitting diode for optoelectronic applications.

Both (A) and (R) are true and (R) is the correct explanation of (A)

Both (A) and (R) are true, but (R) is not the correct explanation of (A)

Population inversion in semiconductor laser diode is achieved by:

Introducing trap centres on p and n sides

Direction: Given question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below.Assertion (A): At microwave frequencies, PIN diode can be used as a fast switch.Reason (R): PIN diode has very high resistance when reverse biased and very low resistances when forward biased.

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is NOT the correct explanation of A

Direction: The following item consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the code given below:Statement (I): PIN photodiodes are preferred to PN diodes.Statement (II): PIN photodiode is a constant voltage generator at a given light level.

Statement I is true but Statement II is false

Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I

Both Statement I and Statement II are individually true but Statement II is not the correct explanation of Statement I

Statement I is true but Statement II is false

Statement I is false but Statement II is true

As compared to an LED, an LCD has the distinct advantage of

Extremely low power consumption

At T = 300 K, the bandgap and the intrinsic carrier concentration of GaAs are 1.42 eV and 106 cm-3, respectively. In order to generate electron-hole pairs in GaAs, which one of the wavelength (\({{\rm{\lambda }}_c}\)) ranges of incident radiation, is most suitable?(Given that: Plank’s constant is 6.62 × 10-34 J-s, the velocity of light is 3 × 1010 cm/s and charge of an electron is 1.6 × 10-19 C)

0.42 μm < \({{\rm{\lambda }}_c}\)< 0.87 μm

.Directions: It consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Photodiodes are not used in relay circuits.Statement (II): The current needed to activate photodiodes is very low even at high light intensities.

Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement(I)

Statement (I) is true but Statement (II) us false

Statement (I) is false but Statement (II) is true

LASER beam of light essentially finds its application in transmission of a signal in the optical fiber communication due to

Low loss transmission of the signal

Incredible speed of signal communication

Low loss transmission of the signal

Bulk availability of LASER sources

Consider a silicon sample at T = 300 K, with a uniform donor density

1.5 × 1013 cm−3 and 8.23 × 1011 cm−3

1.5 × 1013 cm−3 and 7.47 × 1011 cm−3

1.5 × 1013 cm−3 and 8.23 × 1011 cm−3

7.5 × 1013 cm−3 and 3.73 × 1011 cm−3

7.5 × 1013 cm−3 and 4.12 × 1011 cm−3

335 + Mcqs in Devices in Power Electronics Page 1 McqOptions

1.	Directions: Each item consists of two statements, one labeled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Solar insolation is a measure of solar irradiance over a specified period of time.Statement (II): Solar insolation data are commonly used for isolated PV system design.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement(II) are individually true but Statement (II) is not the correct explanation of Statement(I)
C.	Statement (I) is true but Statement (II) us false
D.	Statement (I) is false but Statement (II) is true
Answer» C. Statement (I) is true but Statement (II) us false

Discussion

2.	If a RED/GREEN multi-colour LED is switched fast enough between two polarities, it will produce ________ colour.
A.	Green
B.	Orange
C.	Red
D.	Yellow
Answer» E.

Discussion

3.	Direction: Question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. Examine these two statements carefully and select the answer to this question using the codes given below:Assertion (A): Many semiconductors where minimum energy in the conduction band and maximum energy in the valence band occur at the same value of \(\mathop k\limits^ \to \) (wave vector), are preferred for optical lenses.Reason (R): For such semiconductors, the efficiency of carrier generation and recombination is very high.
A.	Both A and R are individually true and R is the correct explanation of A
B.	Both A and R are individually true but R is not the correct explanation of A
C.	A is true but R is false
D.	A is false but R is true
Answer» B. Both A and R are individually true but R is not the correct explanation of A

Discussion

4.	______ is a type of photo detector, which can convert optical signals into electrical signals.
A.	PIN diode
B.	Avalanche diode
C.	Zener diode
D.	Schottky diode
Answer» B. Avalanche diode

Discussion

5.	A PIN diode consists of:
A.	heavily doped p region, lightly doped n region separated by a high resistivity material
B.	lightly doped p region, lightly doped n region separated by a low resistivity material
C.	heavily doped p and n regions separated by a high resistivity material
D.	heavily doped p region, lightly doped n region separated by a low resistivity material
Answer» D. heavily doped p region, lightly doped n region separated by a low resistivity material

Discussion

6.	Consider the following statements:The main contribution to photoconduction is by1. the generation of electron and hole pair by a photon2. a donor electron jumping into the conduction band because of a photon’s energy3. a valence electron jumping into an acceptor state because of a photon’s energyWhich of the above statements is/are correct?
A.	1 only
B.	2 only
C.	3 only
D.	1, 2 and 3
Answer» B. 2 only

Discussion

7.	An LED has a rating of 2 V and 10 mA. If it is connected to a 6V battery, the minimum value of series resistance is
A.	40 Ω
B.	100 Ω
C.	200 Ω
D.	400 Ω
Answer» E.

Discussion

8.	Assertion (A): A p-n junction diode with low junction depth can be used as a solar cell when illuminated by suitable light (wavelength) at the top thin layer above the junction.Reason (R): A p-n junction diode under no condition can be used as a solar cell. It can be used only as a light-emitting diode for optoelectronic applications.
A.	Both (A) and (R) are true and (R) is the correct explanation of (A)
B.	Both (A) and (R) are true, but (R) is not the correct explanation of (A)
C.	(A) is true, but (R) is false
D.	(A) is false, but (R) is true
Answer» D. (A) is false, but (R) is true

Discussion

9.	Light wave propagation is possible in optical fibre due to a phenomenon called:
A.	Total Internal Reflection
B.	Total External Refraction
C.	Total Internal Refraction
D.	Total External Reflection
Answer» B. Total External Refraction

Discussion

10.	Match List I with List-II and select the correct answer using the code given below the lists: List I List IIA. LED1. Electrical isolatorB. LCD2. Forward biasedC. Optocouplers3. Light reflectors / transmittersD. Photodiode4. Reverse biased
A.	A - 4, B - 1, C - 3, D - 2
B.	A - 2, B - 1, C - 3, D - 4
C.	A - 4, B - 3, C - 1, D - 2
D.	A - 2, B - 3, C - 1, D - 4
Answer» E.

Discussion

11.	An optical amplifier has a population density of electrons in the lower state N1 and in the higher state N2 with the relationship for high amplification as:
A.	N2 ≪ N1
B.	N2 < N1
C.	N2 > N1
D.	N2 = N1
Answer» D. N2 = N1

Discussion

12.	Consider the following statements:1. The efficiency of a light emitting diode (LED) decreases with the injected current.2. The efficiency of a LED increases with a decrease in temperature.3. The light emitted is connected near the junction because most of the carriers are within a diffusion length of the junction.4. Light is emitted in a LED when electrons move from the valence band to the conduction band.Which of these statements are correct?
A.	1, 2. 3 and 4
B.	1 and 2 only
C.	3 and 4 only
D.	2 and 3 only
Answer» E.

Discussion

13.	Population inversion in semiconductor laser diode is achieved by:
A.	Lightly doping p and n sides
B.	Introducing trap centres on p and n sides
C.	Heavily doping p and n sides
D.	Reverse biasing the junction
Answer» C. Heavily doping p and n sides

Discussion

14.	In a photodiode, carriers are generated in the ________.
A.	P region
B.	depletion region
C.	N region
D.	terminal of the diode
Answer» C. N region

Discussion

15.	A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW, the average power over a single pulse duration, in watts, is
A.	1
B.	10
C.	100
D.	1000
Answer» E.

Discussion

16.	In a typical optical fiber the refractive indices of the core and cladding are 1.49 and 1.48 respectively. Find the numerical aperture (NA) of the fiber.
A.	0.1423
B.	0.1563
C.	0.1723
D.	0.1823
Answer» D. 0.1823

Discussion

17.	An LED driver circuit does NOT have a/an _________.
A.	Rectifier circuit
B.	Power resistor
C.	Filter circuit
D.	Oscillator circuit
Answer» E.

Discussion

18.	Optical storage devices use _______
A.	Opto Couplers
B.	Electromagnetic fields
C.	UV light
D.	Lasers
Answer» E.

Discussion

19.	A semiconductor photo device uses
A.	photo emissive effect
B.	photo conductive effect
C.	photo voltaic effect
D.	none of the above
Answer» C. photo voltaic effect

Discussion

20.	Consider the following statements:(a) LASER diode generates monochromatic coherent light which reduces chromatic dispersion(b) LASER source is useful for high power long-distance optical communication(c) LASERs have longer lifetime than LEDs(d) LASER diodes are less temperature-sensitive than LEDsWhich of the above statements are correct?
A.	(a) and (b)
B.	(a) and (c)
C.	(b) and (d)
D.	(b) and (c)
Answer» B. (a) and (c)

Discussion

21.	A photoconductive cell is used for
A.	high frequency application
B.	medium frequency application
C.	low frequency application
D.	all of these
Answer» D. all of these

Discussion

22.	Direction: Given question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below.Assertion (A): At microwave frequencies, PIN diode can be used as a fast switch.Reason (R): PIN diode has very high resistance when reverse biased and very low resistances when forward biased.
A.	Both A and R are individually true and R is the correct explanation of A
B.	Both A and R are individually true but R is NOT the correct explanation of A
C.	A is true but R is false
D.	A is false but R is true
Answer» D. A is false but R is true

Discussion

23.	Direction: The following item consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the code given below:Statement (I): PIN photodiodes are preferred to PN diodes.Statement (II): PIN photodiode is a constant voltage generator at a given light level.
A.	Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I
B.	Both Statement I and Statement II are individually true but Statement II is not the correct explanation of Statement I
C.	Statement I is true but Statement II is false
D.	Statement I is false but Statement II is true
Answer» C. Statement I is true but Statement II is false

Discussion

24.	Photovoltaic cells are ______ materials.
A.	superconductor
B.	conductor
C.	semiconductor
D.	bad conductor
Answer» D. bad conductor

Discussion

25.	Opto-Isolator device consists of the following device/devices _______.
A.	Diodes and resistors
B.	Amplifiers and Capacitors
C.	LEDs and photo-diodes
D.	Laser diodes and LEDs
Answer» D. Laser diodes and LEDs

Discussion

26.	A tunnel-diode is best suited for
A.	Very low frequencies
B.	50 Hz
C.	100 kHz
D.	Microwave frequencies
Answer» E.

Discussion

27.	DC forward voltage is needed to emit light in case of
A.	LED
B.	LCD
C.	Both LED and LCD
D.	Neither LED nor LCD
Answer» B. LCD

Discussion

28.	A Ruby Maser is preferred to Ammonia Maser for microwave amplification because it has:
A.	much greater bandwidth
B.	lower noise figure
C.	better frequency stability
D.	no need for a circulator
Answer» D. no need for a circulator

Discussion

29.	1. The pin diode consists of two narrow, but highly doped, semiconductor regions separated by a thicker, lightly doped material called the intrinsic region.2. Silicon is used most often for its power-handling capability and because it provides a highly resistive intrinsic region.3. The pin diode acts as an ordinary diode at frequencies above 100 MHz.Which of the above statements are correct?
A.	1 and 2 only
B.	1 and 3 only
C.	2 and 3 only
D.	1, 2 and 3
Answer» B. 1 and 3 only

Discussion

30.	In a photoconductive cell, the resistance of the semiconductor material varies with intensity of incident light
A.	directly
B.	inversely
C.	exponentially
D.	logarithmically
Answer» C. exponentially

Discussion

31.	Consider the following statements regarding optocouplers:1. Optocouplers are LEDs driving photodiodes in a single package to provide electrical isolation between input and output2. Optocoupler is an LED driving a phototransistor in a single package that replaces pulse transformers working at input zero crossing3. Optocouplers are used as temporary non-fixed joints between optical fiber terminations.Which of the above statements are correct?
A.	1, 2 and 3
B.	1 and 2 only
C.	1 and 3 only
D.	2 and 3 only
Answer» B. 1 and 2 only

Discussion

32.	As compared to an LED, an LCD has the distinct advantage of
A.	Extremely low power consumption
B.	Providing a silver display
C.	Being extremely thin
D.	Giving two types of displays
Answer» B. Providing a silver display

Discussion

33.	Laser beam is highly intense, monochromatic and coherent, and can be used in monochromatic light and the experiments for the phenomenon of _________.
A.	polarization of light
B.	interference of light
C.	diffraction of light
D.	scattering of light
Answer» C. diffraction of light

Discussion

34.	A pn junction solar cell of area 1.0 cm2, illuminated uniformly with 100 mW cm-2, has the following parameters: Efficiency = 15%, open circuit voltage = 0.7 V, fill factor = 0.8, and thickness = 200 μm. The charge of an electron is 1.6 × 10-19 C. The average optical generation rate (in cm-3s-1) is
A.	0.84 × 1019
B.	5.57 × 1019
C.	1.04 × 1019
D.	83.60 × 1019
Answer» B. 5.57 × 1019

Discussion

35.	For optical sources, the following statements are given:a) They should have large spectral bandwidthb) They should have very narrow spectral line widthc) They should accurately track the electrical input signald) The source should have linearity propertyOut of the above, following are correct:
A.	(a), (b), (c) only
B.	(b), (c) and (d) only
C.	(b) and (c) only
D.	(a), (c) and (d) only
Answer» C. (b) and (c) only

Discussion

36.	If the speed of light in air is represented by e and the speed in a medium is u, then the refractive index of the medium can be calculated using the formula_______.
A.	v/c
B.	c/v
C.	c/(2.v)
D.	(c-v)/c
Answer» C. c/(2.v)

Discussion

37.	At T = 300 K, the bandgap and the intrinsic carrier concentration of GaAs are 1.42 eV and 106 cm-3, respectively. In order to generate electron-hole pairs in GaAs, which one of the wavelength (\({{\rm{\lambda }}_c}\)) ranges of incident radiation, is most suitable?(Given that: Plank’s constant is 6.62 × 10-34 J-s, the velocity of light is 3 × 1010 cm/s and charge of an electron is 1.6 × 10-19 C)
A.	0.42 μm < \({{\rm{\lambda }}_c}\)< 0.87 μm
B.	0.87 μm < \({{\rm{\lambda }}_c}\)< 1.42 μm
C.	1.42 μm < \({{\rm{\lambda }}_c}\)< 1.62 μm
D.	1.62 μm < \({{\rm{\lambda }}_c}\)< 6.62 μm
Answer» B. 0.87 μm < \({{\rm{\lambda }}_c}\)< 1.42 μm

Discussion

38.	A certain Helium-Neon Laser emitting at 633 nm has a line width of 0.002 nm. The coherence length of the laser is given by:
A.	40 cm
B.	5 cm
C.	20 cm
D.	10 cm
Answer» D. 10 cm

Discussion

39.	In optical communication using silica optical fiber, 1 mm spectral width at 1300 mm corresponds to a bandwidth of (assume refractive index of silica optical fiber = 1.5)
A.	150 GHz
B.	120 GHz
C.	80 GHz
D.	90 GHz
Answer» C. 80 GHz

Discussion

40.	.Directions: It consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answer using the code given below:Statement (I): Photodiodes are not used in relay circuits.Statement (II): The current needed to activate photodiodes is very low even at high light intensities.
A.	Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B.	Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement(I)
C.	Statement (I) is true but Statement (II) us false
D.	Statement (I) is false but Statement (II) is true
Answer» E.

Discussion

41.	Consider the following statements:1. The radiation falling on a photodiode is primarily a minority carrier injector.2. The short-circuit current of a reverse biased photodiode under illumination varies exponentially with light intensity.3. The photovoltaic emf of an open-circuited photodiode varies logarithmically with the light-generated short-circuit current.4. The spectral response of a photodiode does not depend upon the frequency of the incident light.Which of these statements are correct?
A.	1, 2, 3 and 4
B.	3 and 4 only
C.	1 and 2 only
D.	1 and 3 only
Answer» E.

Discussion

42.	LASER beam of light essentially finds its application in transmission of a signal in the optical fiber communication due to
A.	Incredible speed of signal communication
B.	Low loss transmission of the signal
C.	Inexpensive installation cost
D.	Bulk availability of LASER sources
Answer» B. Low loss transmission of the signal

Discussion

43.	Consider a silicon sample at T = 300 K, with a uniform donor density
A.	1.5 × 1013 cm−3 and 7.47 × 1011 cm−3
B.	1.5 × 1013 cm−3 and 8.23 × 1011 cm−3
C.	7.5 × 1013 cm−3 and 3.73 × 1011 cm−3
D.	7.5 × 1013 cm−3 and 4.12 × 1011 cm−3
Answer» B. 1.5 × 1013 cm−3 and 8.23 × 1011 cm−3

Discussion

44.	Detection of microwaves is carried out by employing
A.	Vacuum tube diode
B.	Semiconductor diode
C.	Schottky Barrier diode
D.	Field-Effect Transistor
Answer» D. Field-Effect Transistor

Discussion

45.	In SONET standards, the following are the data rates and payloads:(a) SONET - OC - 1 data rate 51.84 Mbps(b) OC – 1 payload 40.112 M bits/s(c) OC - 1 data rate 50.112 Mbps(d) OC - 1 payload 50.112 MbpsWhich of the above is correct for OC - 1
A.	(a) and (b)
B.	(b) and (c)
C.	(c) and (d)
D.	(a) and (d)
Answer» E.

Discussion

46.	An LCD requires a power of __________.
A.	20 W
B.	20 mW
C.	20 μW
D.	20 nW
Answer» D. 20 nW

Discussion

47.	Devices that are under control of computer and are directly connected to computer peripherals are termed as
A.	off-line devices
B.	on-line devices
C.	IN gate device
D.	IF gate device
Answer» C. IN gate device

Discussion

48.	Device that is used to detect bar codes and to indicate points on screen is
A.	digital pen
B.	electrical pen
C.	light pen
D.	hand pencil
Answer» D. hand pencil

Discussion

49.	Four colors availability when shown with 25 lines of text than each line will have
A.	20 characters
B.	40 characters
C.	60 characters
D.	80 characters
Answer» C. 60 characters

Discussion

50.	Small cardboard ticket which includes coded information and is usually attached to the products is usually classified as
A.	tags
B.	coded cardboard
C.	decoded paper
D.	digital cardboard
Answer» B. coded cardboard

Discussion

Explore topic-wise MCQs in Power Electronics.

If a RED/GREEN multi-colour LED is switched fast enough between two polarities, it will produce ________ colour.

______ is a type of photo detector, which can convert optical signals into electrical signals.

A PIN diode consists of:

An LED has a rating of 2 V and 10 mA. If it is connected to a 6V battery, the minimum value of series resistance is

Light wave propagation is possible in optical fibre due to a phenomenon called:

Match List I with List-II and select the correct answer using the code given below the lists: List I List IIA. LED1. Electrical isolatorB. LCD2. Forward biasedC. Optocouplers3. Light reflectors / transmittersD. Photodiode4. Reverse biased

An optical amplifier has a population density of electrons in the lower state N1 and in the higher state N2 with the relationship for high amplification as:

Population inversion in semiconductor laser diode is achieved by:

In a photodiode, carriers are generated in the ________.

A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW, the average power over a single pulse duration, in watts, is

In a typical optical fiber the refractive indices of the core and cladding are 1.49 and 1.48 respectively. Find the numerical aperture (NA) of the fiber.

An LED driver circuit does NOT have a/an _________.

Optical storage devices use _______

A semiconductor photo device uses

A photoconductive cell is used for

Photovoltaic cells are ______ materials.

Opto-Isolator device consists of the following device/devices _______.

A tunnel-diode is best suited for

DC forward voltage is needed to emit light in case of

A Ruby Maser is preferred to Ammonia Maser for microwave amplification because it has:

In a photoconductive cell, the resistance of the semiconductor material varies with intensity of incident light

As compared to an LED, an LCD has the distinct advantage of

Laser beam is highly intense, monochromatic and coherent, and can be used in monochromatic light and the experiments for the phenomenon of _________.

For optical sources, the following statements are given:a) They should have large spectral bandwidthb) They should have very narrow spectral line widthc) They should accurately track the electrical input signald) The source should have linearity propertyOut of the above, following are correct:

If the speed of light in air is represented by e and the speed in a medium is u, then the refractive index of the medium can be calculated using the formula_______.

A certain Helium-Neon Laser emitting at 633 nm has a line width of 0.002 nm. The coherence length of the laser is given by:

In optical communication using silica optical fiber, 1 mm spectral width at 1300 mm corresponds to a bandwidth of (assume refractive index of silica optical fiber = 1.5)

LASER beam of light essentially finds its application in transmission of a signal in the optical fiber communication due to

Consider a silicon sample at T = 300 K, with a uniform donor density

Detection of microwaves is carried out by employing

In SONET standards, the following are the data rates and payloads:(a) SONET - OC - 1 data rate 51.84 Mbps(b) OC – 1 payload 40.112 M bits/s(c) OC - 1 data rate 50.112 Mbps(d) OC - 1 payload 50.112 MbpsWhich of the above is correct for OC - 1

An LCD requires a power of __________.

Devices that are under control of computer and are directly connected to computer peripherals are termed as

Device that is used to detect bar codes and to indicate points on screen is

Four colors availability when shown with 25 lines of text than each line will have

Small cardboard ticket which includes coded information and is usually attached to the products is usually classified as