Question

A photocell cannot be used (1)

(a) for reproduction of sound in motion pictures

(b) in burglar alarms

(c) as a fire alarm

(d) to illuminate a room​

Answer 1

Answer:

a) for reproduction of sound in motion pictures

Answer 2

A photocell cannot be used (b) in burglar alarms

Explanation:

A burglar alarm system consists of a number of electrical components  connected to a property. It uses sensors and contacts to detect movement or  opening of doors and windows, and then a loud alarm sounds to warn nearby people of trespassing. Often considered an important safety feature, the system is versatile in most environments .

Burglar alarm systems can be used in a diverse range of applications, including:

• Industrial areas such as offices, warehouses and factories

• Residential homes and garages

• Commercial premises including shops, restaurants and hotels

• Storage facilities