An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off. It is made of soft iron since it has the property of losing its magnetism very quickly. The soft iron core of the electromagnet makes the magnetic field stronger.

L = inductance is proportional to the number of turns per unit length. So self inductance becomes three times. if turns in a coil is trippled, self inductance become nine times.

Tungsten is used in electric bulb because it has high melting point and it does not oxidize. Thus tungsten filament does not melt even when a large amount of heat is produced due to passage of current through the filament (via heating effect of current).

In a filament type light bulb most of the electric power consumed appears as Infra-red rays. When electricity flows through the fiber, it heats up. Depending on the filament temperature, the radiation is emitted from the filament.

The coil wire in the electric room heater or electric cooking heater is called element.

The composition of electrician solder is Lead-37%, tin-63%.

Mica is used in electrical appliances such as electric iron because mica is a good conductor of heat but a bad conductor of electricity.

While ascending a hill Gear Ratio should be “Either equal to or greater than 1. Gear Ratio is the ratio between angular velocity of input gear to the angular velocity of output gear. It prevents the vehicle from stalling.

Second and third class levers are differentiated by the location of the load.

A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent light bulb; some types fit into light fixtures designed for incandescent bulbs.

When connected in series, the voltages divide in them in the ratio of their resistances. The voltage of 440 V devides in such a way that voltage across 25 w bulb will be more than 220 V. Hence 25 w bulb will fuse.

The electrical domestic tube light gives white fluorescent light because of falling of ultra violet rays on the white inner coating of the tube. The ultraviolet rays have high frequency and shorter wavelength are converted to visible white light with lower frequency and greater wave length.

Electricity is measured in units of power called Watts, named to honour James Watt, the inventor of the steam engine.

Fleming's right-hand rule (for generators) shows the direction of induced current when a conductor attached to a circuit moves in a magnetic field. It can be used to determine the direction of current in a generator's windings.

A current carrying conductor, such as a metal wire, will produce a magnetic field around it because of the motion of charge within the wire itself. This motion produces or sets up a magnetic field around the wire in the form of concentric circles. This electromagnetic effect is described in physics by the Biot-Savart Law, an experimentally deduced inverse-square law. The effect is also described by Ampere’s Law, which is derived from the Biot-Savart Law.

Nichrome is the most common domestic heating element and is found in many household products. Commonly, items such as toasters, hair dryers and heaters use Nichrome coils to pass electricity and give off heat. Nichrome is made of 80 percent nickel and 20 percent chromium, and its high melting point of 1,400 degrees Celsius. Nichrome is a non-magnetic alloy of nickel, chromium, and often iron, usually used as a resistance wire. Patented in 1905, it is the oldest documented form of resistance heating alloy. A common alloy is 80% nickel and 20% chromium, by mass, but there are many others to accommodate various applications. Due to its relatively high electrical resistivity and resistance to oxidation at high temperatures, it is widely used in electric heating elements, such as in hair dryers, electric ovens, soldering iron, toasters, and even electronic cigarettes.

The inside of the bulb being a vacuum, the outside air rushes in when the bulb is broken. The vibrations of the rushing air molecules produce the sound.

The answer is calorimetry, calorimetry is the principle used in calorimeters according to this the net rate of heat generated is same as heat gained by the cooling mechanism. Since there is no work transfer it is relevant.

Q = mcdT refers to Specific Heat formula.

When the switch is ON, in a tube light choke is nothing but the coil/ballast (inductor) which is used to induce the high voltage across it.

1 WH (Watt hour) = 3600 joules

The device used to change the speed of an electric fan is regulator.

Most heating elements use Nichrome 80/20 (80% nickel, 20% chromium) wire, ribbon, or strip. Nichrome 80/20 is an ideal material, because it has relatively high resistance and forms an adherent layer of chromium oxide when it is heated for the first time. Material beneath this layer will not oxidize, preventing the wire from breaking or burning out.
Hence, Nichrome is used as heating elements.

Among all the four water has the highest specific heat.

The specific heat of water is higher than all other common substances. Hence, water is used for heating purposes (as in hot water bottles) and for cooling purposes (as in radiators of cars). Off all the liquids, mercury has the lowest specific heat due to which it is used as a thermometric liquid .

In order to make an electromagnet you need a dry cell batteries, thin coated copper wire and iron nail.

Flemings ''Left hand Rule" is associated with the effect of magnetic field on current.

Steam will produce more severe burns than boiling of water because steam has more heat energy than water due to its latent heat of vaporisation and additionally latent heat of condensation.

There is no current flows between two charged bodies connected together when they have the same potential. For the flow of current between two conductors is that there must be a potential difference. Only then the electrons can flow from a higher potential to a lower potential.

The primary reason that power is transmitted at high voltages is to increase efficiency. As electricity is transmitted over long distances, there are inherent energy losses along the way.

At high operating temperatures, tungsten evaporates from the filament and gradually forms a gray film on the inside of the bulb. The inert gas atoms collide with the evaporating tungsten, causing some of the tungsten atoms to return to the filament.

Water is used as a coolant in automobiles radiators because it has high specific heat capacity. So, it absorbs a large amount of heat for a degree rise in temperature.

It takes 80 calories to melt 1 gram of ice. If 1 g of ice (at 0 degrees Celsius) is given 80 calories, it will melt and the final temperature of the water will be 0. Freezing water at 0 degrees Celsius: It also takes 80 calories to freeze 1 gram of water.

So, resistance of Wire 2 is R/4 as radius is half of wire 1, so area would be 4 times of wire 1.
Now for resistance in series. R= R1 + R2.
Therefore, Final R= R + R/4 = 5R/4

Water pipes burst because the water inside them expands is it gets close to freezing, and this causes an increase in pressure inside the pipe.