PHYSICS [1 Mark Question Answer]

The property of a material due to which it opposes the flow of current through it is known as electrical resistance.

Aluminium and copper.

Electric bell, telephone.

The contact adjustment screw can alter the frequency of the ringing of the bell and also helps to prevent sparking.

Nichrome offer appreciable resistance to the flow of electric current through it. This is why nichrome is used for making heating elements of heaters and toasters.

When the circuit is open the torch bulb stops glowing. When the circuit is closed the bulb remains glowing.

Dry cells are called so because the chemicals stored in them are not in liquid form, but in the form of a thick paste.

The cells that can be used only once are called primary cells. Example : Simple dry cells, button cells, voltaic cells.

The magnetic behaviour of an electromagnets lasts for as long as the current flows through it. The magnetic effect disappears as soon as the supply of electric current is stopped. Hence, electromagnets are also called temporary magnets.

When the path of current starts from one terminal of the cell and ends at the other terminal of the cell without any break, the circuit is called a closed circuit.
When the path of current is broken, the circuit is called an open circuit.

The bulb shown in the given figure is not glowing because the circuit is not closed.

Open circuit.

When the heating element made of nichrome in an electric iron is replaced by copper, the electric current will flow through it and the person will get the shock.

As rubber is an insulator, it prevents the electric current to pass through it. So, electricians wear rubber gloves while working to prevent electric shocks.

The atom will get negatively charged.

Metals contain loosely bound electrons that can participate in the conduction of electricity. Rubber does not have free electrons.