Question 4:
Coupled inductors are connected to a circuit represented by the box in the figure below where $L_1 = 9$
H, $L_2 = 1$ H, and $M = 1.5$ H. Primary is open circuited. If $i_2(t) = 0.4 \sin(10t)$ A, then $v_1(t)$ is (in
volts):
(1) $-6\sin(10t)$
(5) $4 \sin(10t)$
(9) None of these
(2) $-6\cos(10t)$
(6) $4\cos(10t)$
(3) $6\sin(10t)$
(7) $-4\sin(10t)$
(4) $6\cos(10t)$
(8) $-4\cos(10t)$
Answer = (2)
Question 5:
For the circuit below, $R_s = 10 \Omega$, $R_1 = 40 \Omega$, and the LOAD resistor is $R_L = \frac{1}{8} \Omega$. The value of the
turns ratio, $a$, for maximum power transfer to the load resistor is $a =:$
(1) 10
(2) 2
(3) $\frac{1}{40}$
(4) 4
(5) 5
(6) 8
(7) $\frac{1}{8}$
(8) 6
(9) none of above
Answer = (6)
