For a 6F6 triode tube, the plate current, plate voltage, and grid voltage are related by i_p = 41(V_p + 7 V_g)^ 1.41 , where V_p and V_g are in volts and i_p is in microamperes. If the tube is operated at V_p = 250 V and V_g = -20 V , calculate the tube current.

Step-by-step solution

Given the equation for the plate current: i_p = 41(V_p + 7 V_g)^ 1.41 Substitute the given values V_p = 250 V and V_g = -20 V into the equation: i_p = 41(250 + 7(-20))^ 1.41 i_p = 41(250 - 140)^ 1.41 i_p = 41(110)^ 1.41 Using logarithms or a calculator to evaluate (110)^ 1.41 : ₁₀(110^ 1.41 ) = 1.41 ₁₀(110) 1.41 2.0414 2.878 110^ 1.41 10^ 2.878 755.7 Now, substituting this back into the equation for i_p : i_p 41 755.7 A i_p 30984 A Converting microamperes to milliamperes ( 1 mA = 1000 A ): i_p 30.98 mA Rounding to