IES-2010 IES Academy ET (Paper-I) Electronics Engineering (Paper-I)

India’s No 1IES AcademyIES-2010ET (Paper-I)Q34. Assertion (A): For high ‘Q’ circuits, the poles of Y(s) must lie close to the w-axis in the complex frequency plane.Reason (R): Q is inversely proportional to damping factor ξ .(a) Both A and R are true and R is the correct explanation of A(b) Both A and R are true but R is NOT the correct explanation of A(c) A is true but R is false(d) A is false but R is trueQ35. The v-i characteristics as seen from the terminal – pair (A, B) of the networkof Figure (a) is shown in Figure (b). If an inductance of value 6 mH isconnected across the terminal – pair (A, B), the time constant of the systemwill be(a) 3 μsec(b) 12 sec(c) 32 sec(d) Unknown, unless the actual network is specifiedQ36. The unit impulse response of a system is given as c(t) = - 4e -t + 6 e -2t . The stepresponse of the same system for t ≥ 0 is equal to−2t −t −2t −t( a) − 3e + 4e + 1 ( b)− 3e + 4e −1−2t −t −2t −tc −3e −4e − 1 d 3e + 4e −1www.iesacademy.com Email: iesacademy@yahoo.com Page-7__( ) ( )Q37. A coil (which can be modeled as a series – RL circuit) has been designed forhigh Q performance at a rated voltage and a specified frequency. If thefrequency of operation is doubled, and the coil is operated at the samerated voltage, then the Q-factor and the active power P consumed by thecoil will be affected as follows:(a) P is doubled, Q is halved(b) P is halved, Q is doubled(c) P remains constant, Q is doubled (d) P decreases 4 times, Q is doubledQ38. An ideal voltage source will charge an ideal capacitor(a) In infinite time(b) Exponentially(c) Instantaneously(d) None of the aboveQ39. Energy stored in a capacitor over a cycle, when excited by an a.c. source is(a) The same as that due to a d.c. source of equivalent magnitude(b) Half of that due to a d.c source of equivalent magnitude(c) Zero(d) None of the above25, 1 st Floor, Jia Sarai, Near IIT. New Delhi-16 Ph: 011-26537570, 9810958290