How Do You Calculate Charge from Electric Field in Electrostatics?

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To calculate the charge on an isolated metal sphere when the electric field exceeds 20 kV/cm, use the relationship between electric field (E) and charge (Q) given by E = kQ/r², where k is Coulomb's constant and r is the radius of the sphere. The sphere's diameter is 42 cm, making its radius 21 cm. The potential (V) can be calculated using the formula V = Q/(4πε₀r), where ε₀ is the permittivity of free space. The discussion also briefly touches on quantum physics and the photoelectric effect, with a note that X-rays are electromagnetic waves rather than a direct application of the photoelectric effect. Overall, the conversation emphasizes the need for foundational understanding before delving into complex topics.
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we meet again .. here ,i have a question about electrostaatics...
in a particular experiment, a high voltage is created by charging an isolated metal sphere,the sphere has diameter 42 cm and any charge on its surface may be considered as if it were concentrated at its centre. The air surrounding the sphere loses its insulating properties, causing a spark, when the electric field exceeds 20kvcm-1... Calculate the charge on the sphere and its potential,
i know this question involving the equation v=Q/4pi(permittivity of free space)r but how to calculate the charge if we are given electric field?need help...
 
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Use Coulomb's law.
 
hello.. tell me more about quantum physics and photoelectric effect.. Is x-ray one of application of photoelectric effects...
 
Why don't you try doing a bit of research about it on your own first? If you have a specific question, we'd be more than happy to answer that, but explaining the entire thing from scratch would be like reinventing the wheel.

And x-rays are just electromagnetic waves with a wavelength in a specific range. What do you mean by "application?"

cookiemonster
 

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