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A switch is connected in a series with a 75-W bulb to a source of 120V. what is the potential difference across the switch when it is closed?
Wiki User
∙ 13y ago
If the switch, light bulb, and source are all connected in series and the switch is ideal (has no resistance), then the switch acts as a short. There is no potential difference across the short.
Wiki User
∙ 13y ago
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How is electrical current produced?
A potential difference (volts) is set up between the two ends of a conductor. If there are any electrons available to move, then their negative electric charges persuade them to move away from the more negative potential and toward the more positive potential, resulting in current.
Is the sum of the potential differences equal to the voltage applied across them?
Yes for a closed circuit
What happens in a circuit to voltage when current flows?
A: There is a relationship one needs the other both can coexists but not each alone.
What is the difference between voltage and emf?
E.M.F: Is the potential difference between two terminals when there is no current i.e. circuit is open, therefore [EMF = OCV].OCV :open circuit voltage.Voltage: Is the potential difference between two terminals when there is current i.e. closed loopAnswerAn e.m.f. (electromotive force) is a voltage or, more accurately, a potential difference ('voltage' is simply another word for 'potential difference'). However, it is the potential difference that appears across the terminals of a supply when it is not connected to its load. When the supply is connected to a load, this potential difference falls because of an internal voltage drop across the supply's internal resistance. So the simple answer is that an electromotive force is a supply's open-circuit terminal voltage.Another definition is obtained from Kirchhoff's Voltage Law, from which we can say that an electromotive force is equal to the sum of all the all the voltage drops around the circuit, including its internal voltage drops.
Measure the voltage across a voltmeter and a switch?
If the switch is closed (connected) the voltage across it will read 0V. If the switch is open (disconnected) the voltage across it could be anything, it just depends on what the voltage between the wires going into the switch is.
What is required for current to flow through an electrical current?
Potential Source connected across a Closed Circuit Path.
How does voltage produce current?
Voltage across two terminals mean there exists a potential difference, and when the circuit gets closed, due to this potential difference the current flow.
How is electrical current produced?
A potential difference (volts) is set up between the two ends of a conductor. If there are any electrons available to move, then their negative electric charges persuade them to move away from the more negative potential and toward the more positive potential, resulting in current.
What is the difference between electrical potential and electromotive force?
electric potential is potential difference between two points in closed circuit. but electromotive force is potential difference in any open circuit.
Is the sum of the potential differences equal to the voltage applied across them?
Yes for a closed circuit
Which condition must exist between two points in a conductor in order to maintain a flow of charge?
a closed circuit
What happens in a circuit to voltage when current flows?
A: There is a relationship one needs the other both can coexists but not each alone.
Electricity will flow only if an electrical circuit is?
if an electric circuit has potential difference. Electricity will flow only if an electrical circuit is closed.
Is there a difference between an open and closed circuit?
In an open circuit, the electrons cannot flow easily because one of the parts in a circuit is not connected, whereas, in a closed circuit all the parts are connected, therefore, the electrons can flow easily. Hope this helps:)
What is the difference between voltage and emf?
E.M.F: Is the potential difference between two terminals when there is no current i.e. circuit is open, therefore [EMF = OCV].OCV :open circuit voltage.Voltage: Is the potential difference between two terminals when there is current i.e. closed loopAnswerAn e.m.f. (electromotive force) is a voltage or, more accurately, a potential difference ('voltage' is simply another word for 'potential difference'). However, it is the potential difference that appears across the terminals of a supply when it is not connected to its load. When the supply is connected to a load, this potential difference falls because of an internal voltage drop across the supply's internal resistance. So the simple answer is that an electromotive force is a supply's open-circuit terminal voltage.Another definition is obtained from Kirchhoff's Voltage Law, from which we can say that an electromotive force is equal to the sum of all the all the voltage drops around the circuit, including its internal voltage drops.
Measure the voltage across a voltmeter and a switch?
If the switch is closed (connected) the voltage across it will read 0V. If the switch is open (disconnected) the voltage across it could be anything, it just depends on what the voltage between the wires going into the switch is.
Why potential difference across open circuit is more than in closed circuit?
In a closed circuit there is a potential drop due to resistance of wires and battery (internal).AnswerWhen the circuit is closed, the resulting current not only flows through the external circuit, but through the source (battery, generator, transformer, etc.) itself. All sources have an internal resistance, which causes an internal voltage drop, slightly reducing the voltage across the terminals. The larger the current, the larger the internal voltage drop, and the lower the terminal voltage.When the circuit is open, no current flows. So there is no internal voltage drop, and the full voltage appears across the source's terminals.The 'open-circuit voltage' is actually the electromotive force provided by the source.
