Plug it in, but only if you have GFCI! Quiz

Answer: by installing GFCI (Ground Fault Circuit Interrupter) either in the home outlet or in the hair dryer

Since 1991, the US Consumer Product Safety Commission requires that hair dryers have GFCI's installed internally in their circuitry. However, even if the dryer unit does not have GFCI, installing one in the home outlet can prevent severe shocks. If the GFCI senses any loss of current, it immediately switches off power to that circuit. Switching off the device itself is not sufficient to protect from electric shock when it comes into water if the switch is located on the device.

Answer: in a microwave oven

Magnetrons were used in World War II to detect enemy ships. Dr. Percy Spencer, an engineer with Raytheon Corporation, was testing a magnetron for defense research when he discovered that the candy bar in his pocket melted. This intrigued him and led him to experiment with popcorn, eggs, etc till he concluded that microwaves emitted by a magnetron can be used to heat food.

Answer: variable resistor

A resistor used in a circuit causes a voltage drop. In a dimmer, however, this variable resistor is not directly placed on the lamp's circuit (it would get too hot and waste energy) but rather only controls a triac or thyristor performing the actual dimming.

Answer: all of these

The window AC and split AC systems are very similar in their internal workings. Window type air conditioners are small enough to fit in a window, whereas the split-type ACs have the hot and cold sections separated into different units (hence their name).

Answer: induction cooktop

In an induction cooktop, heat is induced into the cookware by an electromagnetic field. This electromagnetic field passes through the cookware, and by its oscillation, induces heat throughout the vessel. For this reason, you can use induction heat to heat an entire pan uniformly and not just its bottom.

Answer: because they are not magnetic, unlike iron or steel

In an induction cooktop, electromagnetic field passes through the cookware. The electromagnetic oscillations in turn produce heat. For this process to occur, the cookware has to be magnetic (e.g. iron, stainless steel).

Answer: power consumed by the blender motor

High wattage blenders, although expensive, are not necessarily better than low wattage blenders. The wattage number displayed by the manufacturer only measures the power consumed by the blender motor. A true indicator of performance is the power generated by the motor, which conveniently, the manufacturers do not display.

Answer: a heating coil loosens the ice cubes from the mold surface

A heating coil runs under the ice mold. As the coil heats up, it warms the mold thereby loosening the ice cubes from their mold surface. I made up the other options listed.

Answer: pop-up toaster

Before the pop-up toaster was invented, a slice of bread had to be turned by hand to toast both sides, which could result in a non-uniform toast. The automatic pop-up toaster was such a success that 500,000 units were sold within a few years.

Answer: infrared rays

Infrared rays exist between microwaves and visible light in the electromagnetic spectrum. The infrared rays emitted by a remote control unit are closer to the visible rays in wavelength and cannot pass through walls (unlike radio waves). This is why you need to sit in front of and point directly at the TV to operate the remote.