An electric circuit

ELECTRIC CIRCUIT 
The path of flow of electricity starting from one terminal of cell and returning to the other is called an electrical circuit. It consists of conducting wires and other resistances (like lamps etc.) between the terminals of a battery, along which an electric current flows.

(a)     Open Electric Circuit : An electric circuit through which no electric current flows is known as open electric circuit. The electric circuit will be open circuit if the plug of the key is taken out or if the connecting wires break from any point.

(b)     Closed Circuit : An electric circuit through which electric current flows continuously is known as closed circuit.

*    For flow of electricity, the circuit must be made of conductors. Insulators in the path of electrical circuits makes the circuit  incomplete.

Ex.3    Look at the circuit given in figure (a) and figure (b). Read the instructions in each case and answer the questions given.

I.    Which bulb B₁/B₂ in figure (a) will glow when 
    (a) only K₁ is closed ?

   (b) K₁ and K₂ are closed ?

   (c) K₁, K₂ and K₃ are closed ?    

   (d) only K₂ and K₃ are closed ?

Sol.    (a) No bulb will glow, (b) Bulb B₁ will glow, (c) B₁ and B₂ both will glow and (d) No bulb will glow. 
II.        Which bulb B₁/B₂/B₃ in figure (b) will glow when
        (a) only K₁ is closed ?
        (b) only K₂ is closed ?
        (c) both K₁ and K₂ both are closed ?    
Sol.    (a) Bulb B₃ will glow, (b) No bulb will glow and (c) All  will glow.

An Electric circuit

An Electric Circuit

An electrical circuit is a simplified representation of an electric circuit element.

Consider an electric cell and a bulb. The terminals of the cell are connected to the terminals of the bulb by the means of electric wires. Such an arrangement of cell and bulb is called an Electric Circuit.

• The circuit is said to be complete in this case because of which electricity will flow and the bulb will glow.
• This uses standard symbols for the components in the circuit and does not show the physical arrangements of the components.
• At present, our daily life on the earth has become nearly impossible without electricity. Homes to big industries depend on electricity.
• Electric current flows in a closed circuit loop. It is a closed-loop in which continuous electric current goes from the supply to the load equipment.
• A closed-loop path, which the current takes is known as an electric circuit.
• When the path of the circuit is closed, current flows through it.
• When there is a break in the path (switch is open) then, the circuit is open and not conducting so the current does not flow.
• One should be careful while setting up an electric circuit. It should be done under supervision.