For the polynomial
P(s) = s⁵ + s⁴ + 2s³ + 2s² + 3s + 15 ,
the number of roots which lie in the right half of the s-plane is

A causal system having the transfer function $$G\left(s\right)\;=\;\frac1{s\;+\;2}$$ is excited with 10u(t). The time at which the output reaches 99% of its steady state value is

A system has poles at 0.01 Hz, 1Hz and 80 Hz; zeroes at 5hz, 100 Hz and 200 Hz. The approximate phase of the system response at 20 Hz is

Given A $$ = \left[ {\matrix{ 1 & 0 \cr 0 & 1 \cr } } \right],$$ the state transition matrix e^At is given by