Energy conservation Elec. Installation system test 03

The efficiency of variable speed drive generally

• decrease with the speed

• increase with the speed

• remains constant with the change in speed

• none of these

The basic function of electronic ballast is

• to ignite the lamp

• to stabilize the gas discharge

• to supply the power to the lamp

• all of these

rotational speed of an AC induction motor depends on the

• the number of poles in stator

• frequency of the applied AC power

• both above

• none of these

A conventional incandescent lamp has a luminous efficiency of

• 10 lumens / watt

• 12 lumens / watt

• 14 lumens / watt

• 14.6 lumens / watt

Maximum demand controller is used to ___________.

• switch off essential loads in a logical sequence

• exceed the demand of the plant

• switch off non-essential loads in a logical sequence

• controls the power factor of the plant

Capacitors with automatic power factor controller when installed in a plant

• reduces active power drawn from grid

• reduces the reactive power drawn from grid

• reduces the voltage of the plant

• increases the load current of the plant

__________ determines the rating of capacitance connected in each step during the first hour of its operation and stores them in memory.

• Maximum demand controller

• Intelligent power factor controller

• Automatic power factor controller

• KILOVAR

Application of occupancy sensors is well suited for ___.

• day light based controllers

• night based controller

• motor controllers

• movement or noise detector in room space

The characteristic of conventional ballast in lighting application is one among the following:

• They have low operational losses than electronic ballasts.

• They have tuned circuit to deliver power at 25 Hz

• They do not require a mechanical switch (starter)

• They have high operational losses and high temperature rise

Electronic soft starters are used for motors to:

• achieve variable speed

• provide smooth start and stop

• improve the loading

• none of the above