Test: Electricity and Circuits - Class 6 MCQ

Plastic is an insulator of electricity.

Aluminium and tap water are conductors of heat.

Tap water, salt solution and metal wire are the examples of conductors

Metal cap is the positive terminal of the electric cell. The Metal disc is the negative terminal.

An incandescent light bulb has a small thin wire with two bigger wires holding it up. This wire is called a filament. The filament is the part of the light bulb that produces light. Filaments in incandescent light bulbs are made of tungsten.

The electric device that easily closes or opens an electric circuit is an electric switch.

Explanation:
- Electric switch: An electric switch is a device that is used to control the flow of electricity in a circuit. It can easily open or close an electric circuit by interrupting or allowing the flow of current.
- Filament: A filament is a wire or thread that is heated to produce light in an electric bulb. It is not responsible for opening or closing an electric circuit.
- Electric bulb: An electric bulb is a device that produces light when an electric current passes through its filament. It is not designed to open or close an electric circuit.
- Electric cell: An electric cell is a device that converts chemical energy into electrical energy. It is not used to open or close an electric circuit.
Therefore, the correct answer is Electric switch (C) as it is specifically designed to easily open or close an electric circuit.

In simple cell battery converts chemical energy into electricity. The chemical reaction produces electrons, which then collect at the negative terminal of the battery. When there is a connection between the positive and negative terminal, the electrons flow to the positive terminal.

The electric current always flows from the higher potential to lower potential. The positive terminal of an electric cell is at higher potential with respect to its negative terminal. Hence, in the given circuit, the current will flow from terminal P to terminal N. 

Positive charge is up and the current is going to the negative charge. That's why the center terminal of an electric cell is always positive.

Petrol and kerosene oil have very low electrical conductivity and hence they are poor electrical conductors (i.e. insulators).