Q. 155.0( 1 Vote )

# The figure is a part of a closed circuit. Find the currents i_{1}, i_{2} and i_{3}

Answer :

IMPORTANT RULE :- WHENEVER THERE ARE CURRENTS COMING FROM DIFFERENT WIRES AND GOING INTO SINGLE ANOTHER DIFFERENT WIRE (THROUGH WHICH THERE IS NO CURRENT COMING) THEN THE CURRENTS ARE ADDED AND IF CURRENT THROUGH ONE WIRE IS GOING INTO TWO DIFFERENT WIRES (WHICH DO NOT HAVE ANY CURRENT RUNNING THROUGH THEM INSTEAD OF THIS CURRENT) THEN THE CURRENT IS DIVIDED IN THEM ACCORDINGLY AND SUBTRACTED FROM THE MAIN COMING CURRENT.

If we know the main current one partition we can find other by using simple maths.

For example- 3A is the main current for forward going 1A and i_{2} , and 1A and i_{2} are the partitions of 3A current.

As there is law of conservation of energy.

There is always conservation of current(charge) ,

So 3 = 1 + i_{2} , by which we can get i_{2} which is = 3-1 = 2A.

Now to calculate i_{1} we must obtain the equation of it , which is

i_{1} + 2 = 3 , i_{1} = 3-2 = 1A.

Now to calculate i_{3} we will look at the point where it is getting divided and by whom that is , what is the main current of i_{3} and the second partition of the main current which is companion with i_{3},

As i_{2} = 2A is the main current and it’s one partition is 1.5A and second partition is i_{3} , so ,

i_{2} = i_{3} + 1.5 , 2 = i_{3} + 1.5 , i_{3} = 2 - 1.5 = 0.5A

Rate this question :

How many electrons flow through an electric bulb every second, if the current that passes through the bulb is 1.6 A.

Tamil Nadu Board - ScienceThe figure is a part of a closed circuit. Find the currents i_{1}, i_{2} and i_{3}

Tamil Nadu Board - Science