Question

A neon gas tube has Von = 60.0 V and Voff = 30.0 V . What resistor value should you choose to go with a 20.0 μF capacitor and a 120 V battery to make a 30.0 Hz oscillator?

Answer 1

Therefore,

The resistor value , R is 9.4 kΩ.

Step-by-step explanation:

Given:

A neon gas tube has

Von = 60.0 V and

Voff = 30.0 V

Capacitor, C = 20.0 μF

Battery , E = 120 V

Frequency = f = 30 hz

`Time\ period =T=(1)/(f)=(1)/(30)=0.033\ s`

To Find:

Resistor , R =?

Solution:

Time period of the wave will be only the charging time of the capacitor,the capacitor will be charged to Von from initial voltage Voff is given by,

`T=RC\ln((E-V_(off))/(E-V_(on)))`

Where,

R = Resistance

C =Capacitance

E = Battery in volts

ln = natural Log (Sign)

Substituting the values we get

`0.033=R* 20* 10^(-6)\ln((120-30)/(120-60))`

`0.033=R* 20* 10^(-6)\ln(1.5)`

`0.033=R* 20* 10^(-6)* 0.176`

`R=9.375* 10^(3)=9.4\ k\Omega`

Therefore,

The resistor value , R is 9.4 kΩ.