What is the primary advantage of electric heating over other heating systems?

Electric heating is economical.

Fill in the blank: The materials commonly used for heating elements in low and medium temperature services are alloys of nickel and ______.

Chromium

True or False: Direct resistance heating has low efficiency compared to indirect resistance heating.

False. Direct resistance heating has high efficiency.

Riddle: I can heat without touching, using waves from a glowing lamp. What am I?

Infrared heating

What is the temperature range that arc heating can achieve?

About 3,000-3,500ºC

Fill in the blank: In induction heating, the power drawn depends upon the voltage and ______ of the charge.

Resistance

Which type of heating method uses eddy currents to produce heat?

High Frequency Eddy Current Heating

True or False: Dielectric heating produces heat outside the material being heated.

False. Dielectric heating produces heat within the material itself.

Riddle: I join metals with heat and pressure, but I’m not a flame. What am I?

Resistance welding

What defines the efficiency of a lamp?

Lamp efficiency is defined as the ratio of luminous flux to the power input.

Fill in the blank: The law that states illumination is inversely proportional to the square of the distance is called ______.

Law of Inverse Square

What is the luminous intensity measured in?

Candela (cd)

True or False: The luminous efficiency of a carbon arc lamp is higher than that of a tungsten filament lamp.

False. The luminous efficiency of a carbon arc lamp is lower.

Riddle: I glow without a filament, my light can change the world, yet I’m just a tube. What am I?

Fluorescent lamp

What is the primary material used for filaments in incandescent lamps?

Tungsten

Fill in the blank: The phenomenon of fluorescence in lamps relies on the discharge through gas or ______.

Vapour

What type of welding process involves no filler rod and uses the base material as an electrode?

Gas Tungsten Arc Welding (GTAW)

True or False: The maintenance factor is defined as the ratio of illumination when the system is dirty to when it is clean.

False. The maintenance factor is the ratio of illumination under normal conditions to when the system is clean.

Riddle: I convert electrical energy into chemical energy, often used for extracting metals and making chemicals. What am I?

Electrolysis

What is the estimated light output depreciation of incandescent lamps over their useful life?

15%

Fill in the blank: The specific consumption of a lamp is defined as the ratio of the power input to the average ______.

Candle power

What does the term 'brightness' or luminance refer to?

Luminous intensity per unit projected area.

True or False: The efficiency of sodium vapour lamps is typically lower than that of mercury vapour lamps.

False. Sodium vapour lamps have higher efficiency.

Riddle: I’m a silent worker that needs no flame, but I can light up a room with my electric glow. What am I?

LED lamp

What is the purpose of a choke in a fluorescent lamp circuit?

It acts as a ballast in running condition and provides a voltage impulse for starting.

Fill in the blank: The arc welding process produces intense heat by an electric arc between the ______ and the metal piece.

Electrode

What type of welding uses a current impulse obtained by discharge from a capacitor?

Self-timing spot welding

True or False: The incandescent lamp is known for its high efficiency and long lifespan.

False. Incandescent lamps have low efficiency and shorter lifespan.

Riddle: I’m often in your home, I twist to save energy but still provide light, who am I?

Compact fluorescent lamp (CFL)

What is the main disadvantage of incandescent lamps compared to other types?

Low efficiency and color light.

Fill in the blank: The luminous flux emitted by a source is measured in ______.

Lumens

What is the role of nitrogen in incandescent lamps filled with inert gas?

To reduce the possibility of arcing.

True or False: The arc voltage in arc welding can vary from 50 to 100 volts.

False. The arc voltage varies from 20 to 40 volts.

What is the efficiency range of modern high-pressure mercury vapour lamps?

75-90 lumens/watt

Riddle: I’m used in welding, require no filler, and work best with AC. What am I?

Gas metal arc welding

What is the main advantage of electric heating over coal, oil, or gas heating?

Electric heating is more economical.

Riddle: I can heat metals and bake potteries, yet I burn without fire, using resistance in my coil. What am I?

Resistance heating

Fill in the blank: The process of heating using electromagnetic induction is known as ______.

Induction Heating