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Current - help11

The amount of current flowing in a circuit is directly proportional to the amount of voltage impressed across its ends by the battery and inversely proportional to the amount of resistance between its ends. Adding more cells to the battery increases the current. Adding more resistance decreases the current.

There are three similar versions of this question. Here is one of the versions:

Version 1:

The circuit at the right shows a 2-cell, 1-bulb circuit; the bulb is a round bulb. Bulb brightness and current is represented by starbursts and arrowtails. Which case – A, B, or C – correctly represents bulb brightness and current if the round bulb is replaced by a higher-resistance long bulb?

Think! Think! Think!
You have to do some thinking and paying attention to detail in this question. First for the thinking part; then we will handle the details. This question asks you to determine how increasing the resistance of a light bulb will affect the current and the bulb brightness. Resistance can be thought of as the hindrance to the flow of charge. So a greater resistance results in a smaller current. And for the same battery voltage, this means a dimmer bulb. So the answer option that you pick will display a smaller current and a dimmer bulb compared to the original round-bulb circuit.

Now for the Details
Once you understand the physics (the paragraph above), you are ready to make some decisions. This involves paying attention to some details. These details include an inspection of the starbursts and of the arrowtails. Starbursts - the rays surrounding a bulb - communicate information about how bright the bulb is. A bright bulb will have a lot of rays around it. A dimmer bulb will have less rays around it. We are looking for a diagram that shows a dimmer bulb (less rays) than the original diagram.

The other detail to pay attention to is the arrowtail representations. The number of tails that trail an arrowhead is an indicator of the amount of current. A large current is represented by many tails. A smaller current is represented by fewer tails. We are looking for a diagram that shows less current (fewer tails) than in the original diagram.

Try this link to The Physics Classroom Tutorial for more help with the concept of electric current:

Electric Current