Numerical Question 21

Please refer to the image for the question

21. A thermometer is observed to exhibit the first order dynamics. The response of thermometer was evaluated by applying a step change in the bath in which thermometer is placed. After 6 seconds the output value was 63.2% of the total applied step change. The thermometer reading at T=55C was put into a bath whose temperature was varied sinusoidally between 50C and 60C with a 60sec/ cycle period of oscillation. The values of phase lag and amplitude ratio respectively are: Ans. 31.96 and 0.8