1
JEE Main 2020 (Online) 2nd September Evening Slot
+4
-1
The displacement time graph of a particle executing S.H.M is given in figure :
(sketch is schematic and not to scale)
Which of the following statements is/are true for this motion?
(A) The force is zero at t = $${{3T} \over 4}$$
(B) The acceleration is maximum at t = T
(C) The speed is maximum at t = $${{T} \over 4}$$
(D) The P.E. is equal to K.E. of the oscillation at t = $${{T} \over 2}$$
A
(B), (C) and (D)
B
(A), (B) and (C)
C
(A) and (D)
D
(A), (B) and (D)
2
JEE Main 2020 (Online) 9th January Evening Slot
+4
-1
A spring mass system (mass m, spring constant k and natural length $$l$$) rest in equilibrium on a horizontal disc. The free end of the spring is fixed at the centre of the disc. If the disc together with spring mass system, rotates about it's axis with an angular velocity $$\omega$$, (k $$\gg m{\omega ^2}$$) the relative change in the length of the spring is best given by the option :
A
$${{m{\omega ^2}} \over {3k}}$$
B
$${{m{\omega ^2}} \over k}$$
C
$${{2m{\omega ^2}} \over k}$$
D
$$\sqrt {{2 \over 3}} \left( {{{m{\omega ^2}} \over k}} \right)$$
3
JEE Main 2020 (Online) 8th January Evening Slot
+4
-1
A simple pendulum is being used to determine th value of gravitational acceleration g at a certain place. Th length of the pendulum is 25.0 cm and a stop watch with 1s resolution measures the time taken for 40 oscillations to be 50 s. The accuracy in g is :
A
4.40%
B
3.40%
C
2.40%
D
5.40%
4
JEE Main 2019 (Online) 10th April Morning Slot
+4
-1
Out of Syllabus
The displacement of a damped harmonic oscillator is given by
x(t ) = e–0.1t cos (10$$\pi$$t + f).
Here t is in seconds. The time taken for its amplitude of vibration to drop to half of its initial value is close to :
A
27 s
B
13 s
C
7 s
D
4 s
EXAM MAP
Medical
NEET