Resistor removed from circuit, which of the following will decrease?

In summary, removing a resistor from a parallel circuit increases resistance and causes more heat to be generated.
  • #1
jan2905
41
0
N resistors (N>2) are connected in parallel with a battery of voltage V0. If one of the resistors is removed from the circuit, which of the following quanities will decrease?

1. the voltage across any of the remaining resistors,
2. the current output by the battery,
3. the total power dissipated in the circuit.


I said 2 (less resistance so less current needed) and 3 (less resistance so less "heat" generated) only. Is this correct?
 
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  • #2


Nope.
 
  • #3


Your justification of "less resistance" is a bit hazy. There are less resistors; but, in parallel, total resistance is 1/RT = 1/R1 + 1/R2 + ... +1/Rn. Taking out one parallel resistor is like closing a lane on the highway.
 
  • #4


lol... thnx skeptic2... for nothing. Well, what would happen? An addition of any number (1/R) would be "more" correct? nope... scratch that... because I am looking strictly at the denominator... 1/2 +1/2 = 1/1 ... so R1 = 2 and R2 = 2, Rt = 1 (less). hmmm... not sure then what would be the answer? any help?
 
  • #5


In removing a parallel resistor - all the others being equal - then resistance must increase.

If the resistance increases what happens to current?

Since P = VI ...
 
  • #6


P decreases right because I decreases?
 
  • #7


but we have N>2 resistors AND they may not be equal.
 
  • #8


jan2905 said:
but we have N>2 resistors AND they may not be equal.

They need not be equal. I was commenting about the simple case that was cited earlier. If you have 2 that are equal, then your resistance is 1/2*R. Take one away and it's R ... it increases.

Extend that simple case to any number of resistors in || and take one away. It increases.
 
  • #9


soooo... i was right then. the current output by the battery (II) because R increases. however, power dissipated would not decrease... it would increase?
 
  • #10


No. Actually you said
I said 2 (less resistance so less current needed) and 3 (less resistance so less "heat" generated) only.

This statement is not correct. It's more resistance that makes for less current. Voltage remains constant.

It's less current that makes for less power consumed - heat generated.

Guessing the right answer for the wrong reason ... not exactly flawless form.
 
  • #11


Okay... R is increased. So, II only because V is constant throughout and R is increased therefore, I decreases. More heat is generated because R is increased, therefore III is not an answer... power dissipation is in the form of heat. I is not an answer because V is constant.

Correct?
 

Related to Resistor removed from circuit, which of the following will decrease?

1. What is a resistor and what does it do?

A resistor is an electronic component that is used to limit the flow of electric current in a circuit.

2. How does removing a resistor affect a circuit?

Removing a resistor decreases the resistance in the circuit, allowing more electric current to flow.

3. How does increasing or decreasing resistance affect the voltage in a circuit?

In a circuit with a constant current, increasing resistance will cause a decrease in voltage, while decreasing resistance will cause an increase in voltage.

4. Will removing a resistor affect the brightness of a light bulb in the circuit?

Yes, removing a resistor will affect the brightness of a light bulb in the circuit. Decreasing resistance will cause the light bulb to become brighter, while increasing resistance will cause it to become dimmer.

5. How does the current in a circuit change when a resistor is removed?

Removing a resistor will increase the current in the circuit. This is because with less resistance, more current can flow through the circuit.

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