In a linear system, an input of 5 sin ωt produces an output of 10 cos ωt. The output corresponding to input 10 cos ωt will be equal to:
- A. +5 sin ωt
- B. -5 sin ωt
- C. +20 sin ωt
- D. -20 sin ωt
Answer: D. -20 sin ωt
Explanation: Input 5 sin ωt yields output 10 cos ωt = 10 sin(ωt + 90°), meaning transfer function H(s) provides a gain of 2 with a +90° phase advance. Input 10 cos ωt yields 20 cos(ωt + 90°) = −20 sin ωt.