## Gcse science revision physics “current in series circuits

The resistance is the proportionality constant in this case. For the time being, we have: In this case, the proportionality constant is the inverse of the resistance. The response is: The following is a statement that defines the relationship between voltage and current: Since I = V / R, voltage and current are directly proportional. 4. current voltage, resistance, and current The present in a circuit is 2.4 A. Although the voltage is increased to four times its original value, the resistance remains unchanged. If the voltage stays constant, how does the resistance change to restore the current to its original value?
Since the current and voltage are directly proportional, the current doubles when the voltage doubles. Which of the following statements best describes the relationship between voltage and current? Since I = V/R, voltage and current are directly proportional. When a potential difference of 120 V produces a current of 0.5 A in a light bulb, what is the resistance of the bulb?

## Ohm’s law

The current is the flow of electricity through an entity, such as a wire (I). It’s measured in amps (A); if the current is very small, it’s measured in milli-amps (mA), with 1000 mA equaling 1A. The voltage is the driving force (electrical pressure) that allows a current to flow. It is measured in volts (V) (Voltage may also be referred to as the potential difference, or electromotive force). The resistance (R) of a material is the property that restricts current flow; the ohm () is the unit of resistance. Impedance is the proper term for resistance to alternating current, but in this case, resistance and impedance are interchangeable.
Ohm’s Law defines the relationship between current, voltage, and resistance. If the temperature stays constant, the current flowing in a circuit is directly proportional to the applied voltage and inversely proportional to the circuit resistance.
The power supply creates electrical pressure (voltage) in the electrical circuit, which is analogous to the pump generating water pressure in the pipe; the current is analogous to the rate of flow of water; and the light bulb provides resistance, which is analogous to the restriction in the water system. The ammeter is the flow meter’s counterpart, and the voltmeter calculates the difference in electrical pressure on either side of the water system’s restriction. The energy used to drive the current through the light bulb, which has a higher resistance than the wire in the circuit, will result in a voltage drop. Similarly, water pressure would be lower at (A) than at (B) (B).

### Ohm’s law

What is the root of current? We may think of a variety of devices that are needed to keep a current flowing, such as batteries, generators, and wall outlets. Voltage sources are loosely described as devices that make a potential difference. When a voltage source is attached to a conductor, it produces an electric field by applying a potential difference V. The electric field, in turn, induces current by exerting force on charges.
Most substances’ current flow is directly proportional to the voltage V applied to them. Georg Simon Ohm (1787–1854), a German physicist, was the first to show experimentally that the current in a metal wire is directly proportional to the applied voltage:
Ohm’s law is the name for this significant partnership. It’s a cause-and-effect relationship, with voltage acting as the cause and current acting as the effect. This is an empirical law, similar to the one for friction, that describes a phenomenon that has been observed experimentally. It is not always the case that a linear association exists.

### 02 – sinusoidal ac voltage sources in circuits, part 1

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The current–voltage characteristics of four devices: a large-resistance resistor, a small-resistance resistor, a P–N junction diode, and a nonzero-internal-resistance battery. The voltage decrease is represented by the horizontal axis, while the current is represented by the vertical axis. The passive sign convention is used in all four plots.
A current–voltage characteristic, also known as an I–V curve (current–voltage curve), is a relationship between the electric current flowing through a circuit, system, or material and the corresponding voltage, or potential difference across it, which is usually expressed as a chart or graph.
A current–voltage characteristic of the system is the relationship between the direct current (DC) across an electronic device and the DC voltage through its terminals in electronics. These diagrams are used by electronic engineers to evaluate a device’s basic parameters and model its behavior in an electrical circuit. The I–V curves, which relate to the regular symbols for current and voltage, are another name for these characteristics.