A triode valve has an amplification factor of 20 and its plate is given a potential of 300 V. What should be the grid voltage to reduce the platecurrent to zero?

Question

A triode valve has an amplification factor of 20 and its plate is given a potential of 300 V. What should be the grid voltage to reduce the platecurrent to zero? (A) 15 V (B) 8 V (C) 25 V (D) 12 V

Tardigrade Admin · Accepted Answer

To reduce the plate current to zero VP should be reduced to zero. Hence for IP=0. Δ Vp =0-300 =-300 V We know that amplification factor, μ=((Δ VP/Δ VG))Δ /P text Coonstant ∴ Δ VG=(Δ VP/μ) =-(300/20) =-15 ∴ Required Grid voltage is -15 V

Q. A triode valve has an amplification factor of 20 and its plate is given a potential of 300V. What should be the grid voltage to reduce the platecurrent to zero?

15 V

8 V

25 V

12 V

To reduce the plate current to zero VP​ should be reduced to zero. Hence for IP​=0. ΔVp​=0−300 =−300V We know that amplification factor, μ=(ΔVG​ΔVP​​)Δ/P​ Coonstant ​ ∴ΔVG​=μΔVP​​ =−20300​ =−15 ∴ Required Grid voltage is −15V

Q. A triode valve has an amplification factor of $20$ and its plate is given a potential of $300 V$ . What should be the grid voltage to reduce the platecurrent to zero?