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AnandM
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Why does electric flux have 'cos θ' in its formula??
To find the flux through a surface you need the component of the field perpendicular to the surface. Taking that component involves the cosine of the angle between the field and the normal to the surface.AnandM said:Why does electric flux have 'cos θ' in its formula??
If you want to maximize the flux through a surface, you want to orient the surface so that its normal is parallel to the field.AnandM said:Why does it have to ve perpendicular? Why not at any other angle?
You use cos θ because you want the component of the field in the direction of the surface normal. Whenever you need a component of a vector in a certain direction, you multiply the magnitude of the vector by the cosine of the angle it makes with that direction.AnandM said:So are we using cos θ because the sin θ component gives 0 flux?
The cosine of the angle (θ) is included in the formula for electric flux because it represents the component of the electric field that is perpendicular to the surface of the object. This perpendicular component is the only part of the electric field that contributes to the electric flux through the surface.
The cosine of the angle (θ) represents the directional relationship between the electric field and the surface of the object. It tells us the amount of the electric field that is passing through the surface perpendicularly, which is the only component that contributes to the electric flux.
The angle (θ) directly affects the value of electric flux by determining the amount of the electric field that is perpendicular to the surface of the object. The greater the angle, the smaller the value of the cosine, and therefore the smaller the value of electric flux.
If the angle (θ) is 90 degrees, the value of the cosine will be 0 and therefore the electric flux will also be 0. This means that there is no electric field passing through the surface perpendicularly, and therefore no electric flux.
The cosine of the angle (θ) can be negative in some cases if the electric field and the surface are oriented in opposite directions. This means that the electric field is passing through the surface at an angle greater than 90 degrees, which results in a negative value for the cosine and therefore a negative value for electric flux.