Q. 82

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Found in: Page 795

### 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 oscillator circuit is important to many applications. A simple oscillator circuit can be built by adding a neon gas tube to an RC circuit, as shown in . Gas is normally a good insulator, and the resistance of the gas tube is essentially infinite when the light is off. This allows the capacitor to charge. When the capacitor voltage reaches a value Von, the electric field inside the tube becomes strong enough to ionize the neon gas. Visually, the tube lights with an orange glow. Electrically, the ionization of the gas provides a very-low-resistance path through the tube. The capacitor very rapidly (we can think of it as instantaneously) discharges through the tube and the capacitor voltage drops. When the capacitor voltage has dropped to a value , the electric field inside the tube becomes too weak to sustain the ionization and the neon light turns off. The capacitor then starts to charge again. The capacitor voltage oscillates between , when it starts charging, and , when the light comes on to discharge it.a. Show that the oscillation period isb. A neon gas tube has . What resistor value should you choose to go with a capacitor and a battery to make a oscillator?

(a) The oscillation period is .

(b) The resistor value is .

See the step by step solution

## Part (a) Step 1 : Given Information.

We need to show the oscillation period.

## Part (a) Step 2 :Simplify

Using formula:

Form formula, we finding value for .

the period oscillations begin when and end when :

End period is:

## Part (b) Step 1 : Given information.

We need to find the dissipated power by the resistor to the current across the capacitor.

## Part (b) Step 2: Simplify

Consider:

First, we have to find value of , from next relation:

Now, we find value: