Q11

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Found in: Page 1082

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# An oil droplet with excess electrons is observed between two parallel electrodes spaced apart. The droplet hangs motionless if the upper electrode is more positive than the lower electrode. The density of the oil is . What is the radius of the droplet?

See the step by step solution

## Step 1: Given information

Oil droplet is placed between the parallel plates of width . There are excess electrons in the oil droplet.

It is given that is the if upper electrode is more positive than the lower the droplet become stationary. (Density of oil )

## Step 2: Equating the electrical force and weight:

Since the droplet become stationary the electrical force exerted by the plates balance the weight of the oil droplet .

Since we got the mass we can find the radius by the density formula.