Root locus on Control Systems related Questions and Answers

Question :   " Which one of the following are correct? The root locus is the path of the roots of the characteristic equation traced out in the s-plane?" 1. " As the input of the system is changed" 2. " As the output of the system is changed" 3. " As a system parameter is changed" 4. " As the sensitivity is changed" Answer :   3 - " As a system parameter is changed"