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

Answer:

Therefore,

The resistor value , R is 9.4 kΩ.

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

$Time\ period =T=\dfrac{1}{f}=\dfrac{1}{30}=0.033\ s$

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,

$T=RC\ln(\dfrac{E-V_{off}}{E-V_{on}})$

Where,

R = Resistance

C =Capacitance

E = Battery in volts

ln = natural Log (Sign)

Substituting the values we get

$0.033=R\times 20\times 10^{-6}\ln(\dfrac{120-30}{120-60})$

$0.033=R\times 20\times 10^{-6}\ln(1.5)$

$0.033=R\times 20\times 10^{-6}\times 0.176$

$R=9.375\times 10^{3}=9.4\ k\Omega$

Therefore,

The resistor value , R is 9.4 kΩ.