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Charges q, 2q, 4q, 8q…. Are placed at distance r, 2r, 4r, and 8r… on x-axis. Find the electric field at origin.

User Yarin
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Final answer:

The electric field at the origin due to a series of charges increasing geometrically and placed at distances also increasing geometrically is calculated as the sum of a convergent geometric series using Coulomb's law for point charges.

Step-by-step explanation:

The question asks for the electric field at the origin due to a series of point charges placed at distances increasing by a factor of 2 and charges increasing by a power of 2. The electric field due to a point charge is given by Coulomb's law, which states that E = k * q / r2, where E is the electric field, k is Coulomb's constant, q is the charge, and r is the distance from the charge.

To calculate the total electric field at the origin, we sum the fields due to each charge, considering that the field due to a positive charge points away from the charge and the field due to a negative charge points towards the charge. Since all charges are placed on the x-axis, the electric fields due to individual charges will either point towards or away from the origin, hence they add up linearly.

For a series of charges q, 2q, 4q, ... at distances r, 2r, 4r, ..., the electric field at the origin can be found by the sum E_total = k * q / r2 + k * 2q / (2r)2 + k * 4q / (4r)2 + ... and so on. This series is a convergent geometric series, and thus its sum can be found using the formula for the sum of an infinite geometric series. Since the ratio between the successive terms of the series is 1/2, the total electric field at the origin can be calculated as E_total = E / (1 - 1/2), where E is the electric field due to the first charge.

User Addeladde
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