Really basic what happens when the switch closed question

In summary, when the switch is closed in the circuit with three identical lamps, lamp C will turn off because the switch and wire in parallel with it have low resistance, causing the majority of the current to flow through the switch instead of the lamp. If there were a resistor in the wire, more current would flow through the lamp.
  • #1
sameeralord
662
3
Hello guys,

I got a small question. It says circuit consists of three identical lamps connected to a battery with a switch as shown in the diagram. When the switch is closed what happens.

I did this really quick on paint.

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they are not allowing me to post URL because I don't have 15 posts. I'll do some spaces and stuff please type the w w w thing properly.

It says that lamps C turns off because no current flows through it. But I don't get it. Shouldn't the current divide and each section get some current. Why is C getting no current when the switch is closed. Any help would be appreciated. Thanks:rolleyes:smile:
 
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  • #2
You are supposed to have both positive and negative current for the lamp to turn on, no?
 
  • #3
sameeralord said:
Hello guys,
...
It says that lamps C turns off because no current flows through it. But I don't get it. Shouldn't the current divide and each section get some current. Why is C getting no current when the switch is closed. Any help would be appreciated. Thanks:rolleyes:smile:

The switch and wire in parallel with the "C" lamp have extremely low resistance.
The "C" lamp will have much higher resistance in comparison.
When the switch is closed, nearly all of the current will flow through the switch.
The current flowing through the lamp will not be sufficient to cause it to illuminate.

For theoretical schoolwork problems, the resistance in the switch and wires are generally assumed to be zero. So when the switch is closed, there will be no voltage drop across the "switch" leg of the circuit. With no voltage drop across the "C" lamp, there will be no current.
 
  • #4
OmCheeto said:
The switch and wire in parallel with the "C" lamp have extremely low resistance.
The "C" lamp will have much higher resistance in comparison.
When the switch is closed, nearly all of the current will flow through the switch.
The current flowing through the lamp will not be sufficient to cause it to illuminate.

For theoretical schoolwork problems, the resistance in the switch and wires are generally assumed to be zero. So when the switch is closed, there will be no voltage drop across the "switch" leg of the circuit. With no voltage drop across the "C" lamp, there will be no current.

Thank you for your help:smile:. I think I get it now. The current took the path of least resistance in this circuit. Let's say there was a resistor in the wire with the switch then you would see more current flow to the globe. Am I right!. Thanks a lot for the help. Really appreciate it. :smile:
 
  • #5
sameeralord said:
Thank you for your help:smile:. I think I get it now. The current took the path of least resistance in this circuit. Let's say there was a resistor in the wire with the switch then you would see more current flow to the globe. Am I right!. Thanks a lot for the help. Really appreciate it. :smile:

Exactly right.
 

What is electricity?

Electricity is a form of energy that is generated by the movement of electrons. It is responsible for powering many of the devices and machines we use every day.

What happens when a switch is closed?

When a switch is closed, it completes a circuit and allows electricity to flow through the circuit. This allows devices to turn on and function.

What is the difference between an open and closed circuit?

An open circuit is when there is a gap or break in the circuit, causing electricity to not be able to flow through. A closed circuit is when there is a complete path for electricity to flow through.

Can a closed switch be dangerous?

A closed switch itself is not dangerous, but it can allow electricity to flow through a circuit, which can be dangerous if not handled properly. It is important to always use caution when dealing with electricity.

What are some common sources of electricity?

Some common sources of electricity include power plants, batteries, and solar panels. These sources generate or store electricity and then distribute it to power devices and machines.

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