Difference between revisions of "Electric Field Strength"
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===Formula=== | ===Formula=== | ||
'''Electric Field Strength''' is given by the general formula: | '''Electric Field Strength''' is given by the general formula: | ||
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*<math>𝐸=\frac{𝐹}{𝑄}</math> | *<math>𝐸=\frac{𝐹}{𝑄}</math> | ||
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Where, | Where, | ||
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*𝐹 is the [[force]] experienced by a [[Electrical Charge|charge]] 'Q' in the field. | *𝐹 is the [[force]] experienced by a [[Electrical Charge|charge]] 'Q' in the field. | ||
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*𝑄 is the [[Electrical Charge|charge]] in that field. | *𝑄 is the [[Electrical Charge|charge]] in that field. | ||
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The '''Electric field strength''' around a point [[Electrical Charge|charge]] is given by: | The '''Electric field strength''' around a point [[Electrical Charge|charge]] is given by: | ||
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*<math>𝐸=𝑘\frac{𝑄}{𝑟^2}</math> | *<math>𝐸=𝑘\frac{𝑄}{𝑟^2}</math> | ||
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Where: | Where: | ||
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*𝑘 is the [[Coulomb's Constant|Coulomb's constant]] | *𝑘 is the [[Coulomb's Constant|Coulomb's constant]] | ||
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*𝑄 is the [[Point Charge|point charge]] causing the field | *𝑄 is the [[Point Charge|point charge]] causing the field | ||
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*𝑟 is the distance from that [[Point Charge|point charge]] | *𝑟 is the distance from that [[Point Charge|point charge]] | ||
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Since; | Since; | ||
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*<math>𝑘=\frac{1}{4\pi\varepsilon_0}</math> | *<math>𝑘=\frac{1}{4\pi\varepsilon_0}</math> | ||
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Then: | Then: | ||
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*<math>𝐸=\frac{1}{4\pi\varepsilon_0}\frac{𝑄}{𝑟^2}</math> | *<math>𝐸=\frac{1}{4\pi\varepsilon_0}\frac{𝑄}{𝑟^2}</math> | ||
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or | or | ||
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*<math>𝐸=\frac{𝑄}{4\pi\varepsilon_0𝑟^2}</math> | *<math>𝐸=\frac{𝑄}{4\pi\varepsilon_0𝑟^2}</math> | ||
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Where: | Where: | ||
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*<math>\varepsilon_0</math>is the [[Permittivity of Free Space|permittivity of free space]] | *<math>\varepsilon_0</math>is the [[Permittivity of Free Space|permittivity of free space]] | ||
Latest revision as of 09:02, 24 May 2024
Key Stage 5
Meaning
Electric field strength is the force per unit charge exerted on a small positive test charge placed at a point in the field.
About Electric Field Strength
- Electric field strength is given by the symbol 𝐸.
- The unit of electric field strength is Newtons per Coulomb (N/C) or volts per metre (V/m).
- The direction of the electric field is the direction of the force that would act on a positive test charge.
- Electric fields can be represented by field lines; the density of these lines indicates the field strength.
Formula
Electric Field Strength is given by the general formula:
- \(𝐸=\frac{𝐹}{𝑄}\)
Where,
The Electric field strength around a point charge is given by:
- \(𝐸=𝑘\frac{𝑄}{𝑟^2}\)
Where:
- 𝑘 is the Coulomb's constant
- 𝑄 is the point charge causing the field
- 𝑟 is the distance from that point charge
Since;
- \(𝑘=\frac{1}{4\pi\varepsilon_0}\)
Then:
- \(𝐸=\frac{1}{4\pi\varepsilon_0}\frac{𝑄}{𝑟^2}\)
or
- \(𝐸=\frac{𝑄}{4\pi\varepsilon_0𝑟^2}\)
Where:
- \(\varepsilon_0\)is the permittivity of free space