Multiple choice

With 10 V dc connected at port A in the linear non-reciprocal two-port network shown below, the following were observed:

(i) 1$\Omega$connected at port B draws a current of 3 A. (ii) 2.5 $\Omega$ connected at port B draws a current of 2 A.

For the same network, with 6 V dc connected at port A, 1 $\Omega$ connected at port B draws 7/3 A. If 8 V dc is connected to port A, the open circuit voltage at port B is

  1. 6 V

  2. 7 V

  3. 8 V

  4. 9 V

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

 on applying Thevenin's equation, for (i) and (ii), we get Vth = 3Rth +3.....(1) Vth = 2Rth +5...(2) subtracting (1) and (2), we get, Rth = 2ohms and Vth = 9V when input was 10V if the input is 6V then Vth = 7/3 * (2+1) =7V Vth = Vb=f(Vs) which implies Vth = mVs + c Vth(10V) = m(10) +C...(3)  Vth(6) = m(6)+ C...(4) Vth(7) = m(7) + C....(5) and Vth(8V) = m(8) + C.....(6) by substituting values in eq. (3 & 4) we get, 9 = 10m +C...(7) and 7 = 6m + C...(8) subtracting(7) and (8), we get, m = 0.5 and c = 4 now, Vth(8V) = m(8)+C = 8 volts