Desperately need introductory CIRCUIT/RESISTOR help

  • Thread starter martinlematre
  • Start date
  • Tags
    Introductory
In summary, In order to make the three light bulbs brightnesses multiples of 1, 2, 3 you would need to use a circuit with 1 light bulb in series with two 10 ohm resistors.
  • #1
martinlematre
41
0

Homework Statement


You’re given a 12.0V battery, 3 light bulbs (of 10.0Ω each), and LOTS of 10.0Ω resistors. Make a circuit so that the light bulbs’ brightnesses are multiples of 1, 2, 3. In other words, if the dimmest light bulb has brightness B, the second dimmest will have brightness 2B, and the brightest will be 3B.

Homework Equations



I've derived a few over a few hours and have drawn it out and mapped and graphed v^2/r (I'm assuming in this case brightness means POWER which is vsquared over r)

The Attempt at a Solution


I just don't see how this is possible to actually map out these 10 ohm resistors with a 10 ohm bulb and a set 12 volt battery. I am under the presumption that by brightness my teacher means power, and having graphed the voltages after crossing a list of quantities of 10 ohm resistors, I cannot find 3 powers that are direct multiples of 2 and 3 of one resistor configuration.

Note that there is no statement for what we are defining as brightness, we have not been taught anything about brightness and that's actually the first time the word has popped up in this course. I don't understand because under my understanding, anything you can construct on a resistor circuit is not linearly related to the brightness, but rather the measurement of lumens of the bulb. Would appreciate if anoyne helped
 
Last edited:
Physics news on Phys.org
  • #2
hi martinlematre! :smile:

hint: parallel :wink:
 
  • #3
tiny-tim said:
hi martinlematre! :smile:

hint: parallel :wink:

I am using parallel circuits. The powers (V^2 over Resistors) are not linearly scaling with 10 ohm resistors
 
  • #4
?? :confused:

V will be the same for parallel circuits
 
  • #5
tiny-tim said:
?? :confused:

V will be the same for parallel circuits

There's a voltage drop across a resistor whose specific quantity is proportional to power (What I'm assuming is what my teacher means by brightness).

V^2/R will be the variable Voltage after drops (And before each lightbulb) squared, over 10ohms (The lightbulb.

Except there is no configuration where that variable voltage after going through X resistors has a 1, 2x and 3x value for power
 
  • #6
martinlematre said:
Except there is no configuration where that variable voltage after going through X resistors has a 1, 2x and 3x value for power

the question says "LOTS" of resistors, so i think you're expected to get only approximately 1:2:3 :wink:

(and it would be more logical to use I, not V)
 
  • #7
tiny-tim said:
the question says "LOTS" of resistors, so i think you're expected to get only approximately 1:2:3 :wink:

(and it would be more logical to use I, not V)

except I am expected to draw/use a very limited program where i can't fit more than 5 or 6 resistors in a circuit without it crashing.

im just making brightness proportional to I.
 
  • #8
Suppose you had 3 light bulbs in series across the 12 volt battery.

Then you rewire the circuit to have 1 light bulb in series with two 10 ohm resistors.

Would the first circuit be exactly 3 times as bright as the second?
 

FAQ: Desperately need introductory CIRCUIT/RESISTOR help

What is a circuit?

A circuit is a path or route through which an electrical current can flow. It is made up of various components such as wires, resistors, capacitors, and switches, which are connected together to form a complete loop.

What is the purpose of a resistor in a circuit?

A resistor is a passive component that is used to limit the flow of current in a circuit. It is often used to control the amount of voltage or current in a circuit, as well as to protect other components from excessive current.

How do I calculate the resistance of a resistor?

The resistance of a resistor can be calculated using Ohm's law, which states that resistance (R) is equal to voltage (V) divided by current (I). This can also be represented as R = V/I. Additionally, the resistance of a resistor can be determined by reading the color-coded bands on the resistor using a resistor color code chart.

What is the difference between series and parallel circuits?

In a series circuit, the components are connected one after the other in a single loop, so the current has only one path to flow through. In a parallel circuit, the components are connected in branches, so the current has multiple paths to flow through. This results in different voltage and current values in each type of circuit.

How do I troubleshoot a circuit with a resistor?

If a circuit is not functioning properly, the first step is to check the resistor for any signs of damage or defects. If the resistor appears to be working correctly, then you can use a multimeter to measure the resistance and ensure it is within the specified range. If the resistance is too high or too low, the resistor may need to be replaced. You can also check the connections and other components in the circuit to ensure they are properly connected and functioning.

Back
Top