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Why potential difference across open circuit is more than in closed circuit?
Wiki User
∙ 12y ago
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.
Wiki User
∙ 12y ago
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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.
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.
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?
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.
What is difference between voltage and emf?
An electromotive force (e.m.f.) is the open-circuit, or no-load, potential difference provided by a source -such as a battery or generator. For a closed circuit, an e.m.f. is the sum of the voltage-drops around any closed loop, including the internal voltage drop of the source.A potential difference (voltage) can exist across any circuit component. For example, the fact that current is flowing through each of several resistors in a series circuit means that there must be an individual potential difference across each of those resistors (which we also term 'voltage drop').An electromotive force is the name we give to the open-circuit potential difference provided by a generator, battery, etc. For example, the open circuit potential difference of a battery would be its electromotive force.So, if we use a series resistive circuit as an example, the battery would provide the electromotive force, while voltage drops would then appear across its internal resistance, and across each of the resistances. The magnitude of the electromotive force is then equal (but acting in the opposite sense) to the sum of the voltage drops, including the internal voltage drop.Many textbooks use the symbol, E, to represent an electromotive force, and V to represent potential difference. So, Kirchhoff's Voltage Law, for example, will often be seen written as: E = V1 + V2 + V3 + etc.
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.
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.
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 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.
Which condition must exist between two points in a conductor in order to maintain a flow of charge?
a closed circuit
What is required for current to flow through an electrical current?
Potential Source connected across a Closed Circuit Path.
Why is an electricity not flow in an open circuit?
The electricity will flow from higher potential to lower potential in a closed circuit.
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.
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?
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.
What is difference between voltage and emf?
An electromotive force (e.m.f.) is the open-circuit, or no-load, potential difference provided by a source -such as a battery or generator. For a closed circuit, an e.m.f. is the sum of the voltage-drops around any closed loop, including the internal voltage drop of the source.A potential difference (voltage) can exist across any circuit component. For example, the fact that current is flowing through each of several resistors in a series circuit means that there must be an individual potential difference across each of those resistors (which we also term 'voltage drop').An electromotive force is the name we give to the open-circuit potential difference provided by a generator, battery, etc. For example, the open circuit potential difference of a battery would be its electromotive force.So, if we use a series resistive circuit as an example, the battery would provide the electromotive force, while voltage drops would then appear across its internal resistance, and across each of the resistances. The magnitude of the electromotive force is then equal (but acting in the opposite sense) to the sum of the voltage drops, including the internal voltage drop.Many textbooks use the symbol, E, to represent an electromotive force, and V to represent potential difference. So, Kirchhoff's Voltage Law, for example, will often be seen written as: E = V1 + V2 + V3 + etc.
What is the function of emf in electric circuit?
An electromotive force is the potential difference developed by a voltage source, and is necessary to cause current to flow through a circuit. Strictly-speaking, it is the open-circuit potential difference of a battery, generator, etc. An alternative definition is that an e.m.f. is equal to the sum of the voltage drops around any closed loop, including any internal voltage drop.
