Q. 71

Expert-verified
Found in: Page 657

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

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

# One type of ink-jet printer, called an electrostatic ink-jet printer, forms the letters by using deflecting electrodes to steer charged ink drops up and down vertically as the ink jet sweeps horizontally across the page. The ink jet forms diameter drops of ink, charges them by spraying electrons on the surface, and shoots them toward the page at a speed of . Along the way, the drops pass through two horizontal, parallel electrodes that are wide, and spaced apart. The distance from the center of the electrodes to the paper is . To form the tallest letters, which have a height of , the drops need to be deflected upward (or downward) by . What electric field strength is needed between the electrodes to achieve this deflection? Ink, which consists of dye particles suspended in alcohol, has a density of .

The electric field strength needed is

See the step by step solution

## Step 1 : Given Information and Formula used

Given :

The diameter of drops of ink :

Charge on the droplets :

Speed : 20 m/s.

Dimensions of electrodes : wide, apart.

The distance from the center of the electrodes to the paper : .

Height of the tallest letters :

The drops are deflected upward (or downward) by :

Ink has a density of :

Theory used :

Mass :

Maximum deflection :

Newton's law :

Field strength :

## Step 2 : Calculating the maximum deflection

First, we must locate mass :

Then there's charge :

We now have a value for maximum deflection

## Step 3 : Calculating the required electric field strength needed between the electrodes

We can now calculate acceleration ay using the following relation:

Finally, field strength :