$$v\left(t\right)\;=5\left[\cos\left(10^6\mathrm{πt}\right)\;-\;\sin\left(10^3\mathrm{πt}\right)\times\sin\left(10^6\mathrm{πt}\right)\right]$$ represents

Match the following with List-1 with List-2

List-1
(a) Very low response at very high frequencies.
(b) Overshoot
(c) Synchro-control transformer output

List-2
(1) Low pass systems
(2) Velocity damping
(3) Natural frequency
(4) Phase-sensitive modulation
(5) Damping ration

The poles of a continuous time oscillator are ___________.

Tachometer feedback in a d.c. position control system enhances stability.