The slope of plate characteristic and mutual characteristic curves of a triode value is 0.02 mA/V and 1 mA/V. The amplification factor of triode value is:
The plate resistance and the amplification factor of a triode are 10KΩ and 20. The tube is operated at plate voltage 250 V and grid voltage -7.5 V. The plate current is 10 mA. (a) To what value should the grid voltage be changed so as to increase the plate current to 15 mA? (b) To what value should the plate votage be changed to take the plate current back to 10 mA?