REM B LVL 2

Question 1

AC resistance of a diode was found to be r1 and r2, when measured with two different values of diode current i.e. 10 mA and 25 mA respectively, for the
same diode voltage. Which of the
following options hold true?

A. r1>r2
B. Can’t be determined
C. r1<r2
D. r1=r2

Answer 1

A. r1>r2

ri >r2 as AC resistance is inversely
proportional to the diode current.

Question 2

The output frequency of a half-wave
rectifier is ___ the input frequency.

A. none of these choices
B. equal to
C. twice

Answer 2

B. equal to

Question 3

To increase the input resistance in
differential amplifier, replace the
transistor by

A. All of the mentioned
B. Darlington pair
C. Current mirror

Answer 3

B. Darlington pair

Higher value of input resistance can be
obtained by using Darlington pair in
place of transistor.

Question 4

What is the main advantage of resonant
cavity and quantum-dot LEDs?

A. They are immune to temperature changes.
B. They are highly resistant to electrical
current.
C. They offer precise control over emitted
wavelengths.

Answer 4

C. They offer precise control over emitted
wavelengths.

Question 5

Which type of LED structure is also
known as vertical-cavity surface-
emitting lasers (VCSELs)?

A. Surface emitter LEDs
B. Planar LED
C. Dome LED

Answer 5

A. Surface emitter LEDs

Question 6

What is the primary function of a
photodiode?

A. To generate heat when exposed to light
B. To convert light into sound waves
C. To generate a current or voltage when
exposed to light
D. To amplify electrical signals

Answer 6

C. To generate a current or voltage when
exposed to light

Question 7

Which direction do electrons move in a photodiode under the influence of the electric field?

A. Toward the photon source
B. Toward the n-side
C. Toward the depletion region
D. Toward the p-side

Answer 7

B. Toward the n-side

Question 8

Pirani Gauge is an example of which
type of transducer?

A. Light transducer
B. Temperature transducer
C. Pressure transducer

Answer 8

C. Pressure transducer

Pirani Gauge is a pressure transducer.
It’s a thermal conductivity gauge used to detect pressure in vacuum conditions. It was named after a German physicist
“Marcello Stefano Pirani” who invented
it in 1906.

Question 9

The IC LM35 is used as which type of
sensor?

A. Mechanical sensor
B. Light sensor
C. Pressure sensor
D. Temperature sensor

Answer 9

D. Temperature sensor

The LM35 IC manufactured by Texas
Instruments is used as a temperature
sensor. The output voltage generated by
this IC is linearly proportional to the
temperature in Centigrade. The output voltage is directly proportional to the temperature.

Question 10

What is measured by a hall effect
transducer?

A. Electric flux
B. Magnetic field
C. Electric Field

Answer 10

B. Magnetic field

Hall effect transducers or Hall effect
sensor is used for measuring the
magnitude of the magnetic field. The
output voltage produced by the sensor
is directly proportional to the strength of
the magnetic field passing through it.

Question 11

What is the full form of LVDT with
respect to displacement transducer?

A. Liquid visible differential transformer
B. Linear variable differential transformer
C. Linear variable differential temperature

Answer 11

B. Linear variable differential transformer

LVDT stands for Linear variable
differential transformer. It is a
displacement transducer that converts
rectilinear motion to electric signals.
They are used widely due to their
robustness.

Question 12

Consider the following statements
regarding PLC
1. It was developed to replace the
microprocessor.
2. Wiring between devices and relay
contacts are done in its program.
3. Its |/0 interface section connects it
to external field devices.
4. It requires extensive wiring in the
application.
Which of the above statements are
correct?

A. A and C
B. B and D
C. B and C

Answer 12

C. B and C

Question 13

In a PLC, which of the following is NOT a
subpart of the CPU?

A. Power supply
B. Microprocessor
C. Memory
D. Programmer

Answer 13

D. Programmer

Question 14

A technology for the application of
mechanical, electronics, and computerbased systems to control and operate the systems is called ___

A. Microprocessor-based systems
B. Sequential Controller
C. Automation

Answer 14

C. Automation

Question 15

The CPU module in the PLC is used to:

A. Control the outputs only
B. Execute the control program only
C. Read inputs only
D. Read inputs, execute the control
program and update output

Answer 15

D. Read inputs, execute the control
program and update output

Question 16

What is the function of the Fire Alarm Control Panel (FACP) in a Fire Safety System?

A. It provides a user-friendly interface for
managing the system.
B. It detects unauthorized entry into the
building.
C. It processes signals from smoke detectors and triggers appropriate responses.

Answer 16

C. It processes signals from smoke detectors and triggers appropriate responses.

Question 17

A university campus wants to upgrade
its HVAC control system to reduce
energy consumption while ensuring
comfort in each building. Which type of HVAC control system would be a good fit?

A. Electromechanical control systems
B. Pneumatic control systems
C. Direct digital control systems

Answer 17

C. Direct digital control systems

Question 18

What are Fire Safety Systems primarily
designed to protect buildings from?

A. Theft and burglary
B. Water damage
C. Fire damage

Answer 18

C. Fire damage

Question 19

Which component is responsible for detecting occupancy and adjusting lighting accordingly?

A. Lighting fixtures
B. Dimmers
C. Video Systems
D. Occupancy sensors

Answer 19

D. Occupancy sensors

Question 20

Which of the following benefits is NOT
associated with a well-implemented
BMS?

A. Higher energy consumption due to
automated control
B. Real-time monitoring and reporting of
occupant comfort
C. Enhanced equipment performance and
extended lifetime

Answer 20

A. Higher energy consumption due to
automated control