Question

A Investigation #11: Non-Identical Bulbs in Series and Parallel All of the circuits you have investigated so far have involved identical bulbs. If two bulbs are identical and one bulb is brighter, then the brighter bulb must have a larger current thru it. Furthermore, the larger current must be caused by a larger potential difference. In this investigation, you will study circuits for which the bulbs are not identical. We will illustrate that two Spherical bulbs are not identical by changing the shapes of the bulbs. The bulbs that we used in all previous investigations have been illustrated with a spherical Oblong globe. The new bulb will be illustrated with an oblong globe. Note When you click on a light bulb in the PhET simulation, a slider that lets you set the resistance of the bulb will appear at the bottom of the simulation window. By default, bulbs are set to 1012. This is resistance we have been using for all spherical bulbs. In this investigation, when you require an oblong bulb, set its resistance to 2512. Prediction 1 Predict whether the spherical or the oblong bulb will be brighter when they are connected in series as is shown in the circuit above. Prediction 2 Predict how the current through the spherical bulb compares to the current through the oblong bulb.

Answer 1

Prediction 1 : The oblong and the spherical bulb has resistance of 25 ohm and 10 ohm respectively. as the resistance in the oblong is more , hence the potentail accross the oblong will be more an hence the oblong will glow brighter

prediction 2 : as they are connected in series hence the current through the bulbs will be same in nature .

answer 1 : The prediction made in 1 & 2 are correct .

answer 2: The brightness of the bulb depends upon the current and potential difference across it . As from ohm's law we know potential difference depends upon the resistance , hence we can say that the brightness is not solely depends upon the current