Higher Study | Communication Systems | Optical Sources and Detector

Study the given figures. Identify the elements from 1 to 4 and select the option that shows their correct names

ক

1: Zener diode, 2: Photo diode, 3: LED diode, 4: Junction diode

খ

1: LED diode, 2: Junction diode, 3: Zener diode, 4: Photo diode

গ

1: Photo diode, 2: LED diode, 3: Junction diode, 4: Zener diode

ঘ

1: Junction diode, 2: Zener diode, 3: Photo diode, 4: LED diode

What is the typical range of the forward voltage of an LED?

ক

5-12 V

খ

1.7-3.3 V

গ

5-12 mV

ঘ

1.7-3.3 mV

What colour LED lamp is commonly used for domestic use?

ক

White

খ

Black

গ

Red

ঘ

Green

Which of the following is used in the specification of optical detectors?

ক

Sensitivity

খ

Noise equivalent power

গ

Electron movement

ঘ

Polarization

Which one of the following can be used as a photo detector in Fiber Optic Communication?

ক

Tunnel diode

খ

LED

গ

PIN diode

ঘ

LASER diode

Which of the following is NOT a function of the LED driver?

ক

Preventing damage against EMI

খ

Preventing damage to LEDs by Regulating the forward voltage (VF)

গ

Avoiding thermal runaway

ঘ

Delivering a constant current to the LED

When the LED lights need a range of voltages to operate, Which of the following drivers is best suited for the job?

ক

Constant frequency

খ

Constant Voltage

গ

Constant Impedance

ঘ

Constant Current

What is the use of an LED driver?

ক

It converts DC to AC

খ

It converts AC to DC

গ

It converts AC to AC

ঘ

It converts DC to DC

What is the forward voltage of LED?

ক

0.6 Vdc

খ

1.5 Vdc to 3 Vdc

গ

0.3 Vdc

ঘ

1.8 Vdc to 3.3 Vdc

What is the output of an LED driver?

ক

Chopped AC

খ

Pulsating DC

গ

DC

ঘ

AC

Which of the following devices removes or recovers information from a signal?

ক

De-multiplexer

খ

Detector

গ

Converter

ঘ

Multiplexer

Which of the following LED colours is NOT present in an LED TV panel?

ক

Green

খ

White

গ

Red

ঘ

Blue