Question

The diagram that shows the position of a simple pendulum at equal time intervals while oscillating is
A.
B.
C.
D.

Answer 1

We must know the laws of oscillation of a simple pendulum. A simple pendulum consists of a mass hanging from a string of length and fixed at a pivot. When displaced to an initial angle and released, the pendulum will swing back and forth with the periodic motion.

Complete answer:
With the assumption of small angles, the frequency and time period of the pendulum are independent of the initial angular displacement amplitude. A pendulum will have the same period regardless of its initial angle.

If we pull the bob of the pendulum a little towards our right and then release it, it will be seen to come back and move on to the left (the other side) at an equal distance on the other side of the mean (initial position) and then go on repeating this back and forth motion between the two extreme positions. We call that the simple pendulum is oscillating.

The period of a pendulum does not depend on the mass of the ball, but only on the length of the string. Two pendulums with different masses but the same length will have the same period. Two pendulums with different lengths will have different periods; the pendulum with the longer string will have a longer period. From all the figures given the first figure depicts the true nature of the oscillation of a simple pendulum.

Hence option A is correct.

Note: Time period is the time taken by a pendulum bob to make one complete oscillation. We can consider the oscillation in a simple pendulum as simple harmonic motion because if we plot a graph of the displacement of the mass and the time, it shows an SHM motion curve.