The bob of a simple pendulum is released from rest from its extreme position. Which of the following is true for the bob when it reaches the opposite extreme position?

A teacher is planning for a class on a simple pendulum with her students. She has the following materials: A. Thin elastic string B. Lightweight spring C. Cotton thread Which of the above materials can be chosen as the string of a simple pendulum?

Which of the following changes in a simple pendulum will lead to an increase in its time period?