A torch requires 3 cells. Show the arrangement of the cells, with a diagram, inside the torch so that the bulb glows.

The diagram shown below is correct arrangement to join three electric cell inside the torch so that the bulb glows,

The current start from the positive terminal of the cell and will come up back into the negative terminal of the cell.

If a bulb require three electric cell the most important thing is how you arrange the cell. The correct arrangement is that when positive terminal of one cell is attached to the negative terminal of the another.

Now, it will work like current from one cell will leave and will enter into another cell {from negative terminal of the second cell} there it will add with the current of second cell and they both will leave {from positive terminal of the second cell} and then they will enter into third cell{ through the negative terminal of the third cell} after that all the current sum up and will go into the circuit from the positive terminal of the third cell.

The key point here is Current can leaves from positive terminal of the cell only and enter into cell from negative terminal, we have to fulfill these two condition to make this arrangement.