Which of the following motor is very efficient and is used in direct drive applications:

Velocity pressure is the backward force of air within a duct.

When fans are operated in parallel, total air flow is equal to:

Capacitor motors that are connected directly to fans or blowers are usually arranged to operate at one speed.

When two identical fans are operated in series then the cfm is doubled:

Which of the type of fans are somewhat lighter and require considerably less space.

Which of the following voltage rating of fan are less likely available in market

Total pressure of a fan is the rise of pressure from fan outlet to fan inlet

______ efficiency of a fan is the mechanical efficiency multiplied by the ratio of static pressure to total pressure

The horsepower required for any fan or blower varies directly as the _______ of the speed, provided that the area of the discharge orifice remains unchanged.

In which of the following exhaust fan air flows radially (diverging from the center):

Hood exhaust fans involving ductwork are predominantly ______ , and are used especially in handling hot or corrosive fumes.

Wall fans are predominantly of the _______ type, since they operate against little or no resistance.

In large industrial installations (mechanical draft fans required), which of the following motors are used for attaining different speeds:

Net intake air provided shall be atleast ________ greater than the exhaust fan opening: