Electrical Engineering Interview Questions|Basic Electrical Engineering Questions & Answers

Electric cells are the source of electric current in a torch.

Electric geysers, room heaters, electric toasters, electric iron etc

Electric bells, loudspeakers, telephone receivers, cranes etc.

The filament of an electric bulb is made of tungsten
which has a very high melting point.

Electromagnets are used in electric bells.

The path through which electric charges move from one point to other is called an electric circuit.

Key can be placed anywhere in the circuit.

The positive terminal of one cell is connected to the negative terminal of the next cell to prepare a battery.

There are three effects of electricity :
(i) Heating effect (ii) Chemical effect
(iii) Magnetic effect

Resistance is a physical quantity that measures the opposition offered to the flow of current by a conductor.

The common sources of electricity are cells,
batteries and the mains.

The meaning of ‘battery’ is an arrangement of
a number of cells.

MCBs are switches which automatically turn off when current in a circuit exceeds the safe limit.

On connecting appliances in parallel to the mains, each appliance can be used independently of the others and each has the potential difference of the mains across it.

Electric bulbs have a filament made of tungsten. This filament gets so hot when an electric current flows through it that it glows. So, an electric bulb gets hot as well.

Due to the magnetic effect of current, the current carrying wire behaves as a magnet. So a magnetic needle gets deflected when it is placed near a current carrying wire.

The heat developed in a conductor due to the passage of electric current depends on the following factors :
(i) Current flowing through the conductor
(ii) Time of passage of current
(iii) Nature of conductor
(iv) Physical characterstics of conductor (e.g., length and thickness)

Electromagnets can be prepared by using the magnetic effect of electric current. It consists of long, coiled copper wire wrapped around an iron rod. When current is passed through the wire, it behaves like a magnet, called electromagnet

Applications of electromagnets :
(i) Electromagnets are used in cranes for lifting heavy loads.
(ii) Electromagnets are used in electric bells, speakers, etc.

Battery is a combination of two or more cells. This can be constructed by placing cells properly on cell holder such that the positive terminal of one cell is connected to the negative terminal of the other. A piece of wire is connected to each of the two metal clips on the cell holder.

We should never touch a lighted electric bulb as it may be very hot and our hand may get burnt badly.

Fuse is a safety device which prevents our houses, appliances and electric circuits from electrical hazards at the time of the short circuiting or overloading. The fuse works on the basis of heating effects of the electric current. If by an accident the current exceeds a certain limit this devise becomes overheated and melts which breaks the circuit and supply of electricity is stopped. In this way it helps in prevention of damage.

Compass needle is a tiny magnet which points in north-south direction. When it is brought close to a magnet then needle gets deflected. When compass needle is brought near to a current carrying wire then it is deflected and when direction of current is changed then direction of deflection of compass needle is also changed. This shows the magnetic effect of electricity.

The electromagnet works on the basis of magnetic
effect of electricity.

The coil of wire used in heating devices is known as heating element.