Physics · Class 11 · Chapter 13
Oscillations
9 lessons 75 min 2 simulations
This chapter is about motion that goes back and forth about a fixed point: how to describe it with period, frequency, amplitude and phase, why a restoring force proportional to displacement gives simple harmonic motion, how energy moves between kinetic and potential forms, and why a pendulum swinging through small angles keeps time. It is the foundation for the next chapter on waves and for AC circuits in Class 12.
What the exam asks
NEET asks for periods of spring-mass systems and pendulums, phase relations between x, v and a, energy at a given displacement, and whether a given function or force law describes SHM. Marks are lost by mixing ν with ω, by using degrees inside the sine, by forgetting that K and U repeat every T/2, and by assuming that a pendulum's period depends on the mass of its bob.
Lessons
9 lessons · 75 min
1Periodic and oscillatory motionNCERT §13.1, §13.26 min2Period, frequency and displacementNCERT §13.2.1, §13.2.27 min3Simple harmonic motion: amplitude, phase and angular frequencyNCERT §13.37 min4SHM as the shadow of uniform circular motionNCERT §13.47 min5Velocity and acceleration in SHMNCERT §13.57 min6Force law for SHM: F = −kxNCERT §13.610 min 1 sim7Energy in SHMNCERT §13.77 min8The simple pendulumNCERT §13.810 min 1 sim9Chapter reviewMust-know facts, traps and formulas14 min