Assertion and Reason Questions for Class 11 Physics Chapter 14 Oscillations
Directions: (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.
(c) If assertion is true but reason is false.
(d) If the assertion and reason both are false.
Q.1. Assertion : Sine and cosine functions are periodic functions.
Reason : Sinusoidal functions repeats it values after a definite interval of time.
Q.2. Assertion : Simple harmonic motion is a uniform motion.
Reason : Simple harmonic motion is not the projection of uniform circular motion.
Q.3. Assertion : Acceleration is proportional to the displacement. This condition is not sufficient for motion in simple harmonic.
Reason : In simple harmonic motion direction of displacement is also considered.
Q.4. Assertion : The graph between velocity and displacement for a harmonic oscillator is a parabola.
Reason : Velocity changes uniformly with displacement in harmonic motion.
Q.5. Assertion : When a simple pendulum is made to oscillate on the surface of moon, its time period increases.
Reason : Moon is much smaller as compared to earth.
Q.6. Assertion : All oscillatory motions are necessarily periodic motion but all periodic motion are not oscillatory.
Reason : Simple pendulum is an example of oscillatory motion.
Q.7. Assertion : Resonance is special case of forced vibration in which the natural frequency of vibration of the body is the same as the impressed frequency of external periodic force and the amplitude of forced vibration is maximum.
Reason : The amplitude of forced vibrations of a body increases with an increase in the frequency of the externally impressed periodic force.
Q.8. Assertion : The graph of total energy of a particle in SHM w.r.t., position is a straight line with zero slope.
Reason : Total energy of particle in SHM remains constant throughout its motion.
Q.9. Assertion : The frequency of a second pendulum in an elevator moving up with an acceleration half the acceleration due to gravity is 0.612 s–1.
Reason : The frequency of a second pendulum does not depend upon acceleration due to gravity.
Q.10. Assertion : Damped oscillation indicates loss of energy.
Reason : The energy loss in damped oscillation may be due to friction, air resistance etc.
Q.11. Assertion : The percentage change in time period is 1.5%, if the length of simple pendulum increases by 3%.
Reason : Time period is directly proportional to length of pendulum.