1
JEE Main 2019 (Online) 9th January Evening Slot
+4
-1
Out of Syllabus
A musician using an open flute of length 50 cm producess second harmonic sound waves. A person runs towards the musician from another end of hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to :
A
666 Hz
B
753 Hz
C
500 Hz
D
333 Hz
2
JEE Main 2019 (Online) 9th January Morning Slot
+4
-1
A heavy ball of mass M is suspendeed from the ceiling of a car by a light string of mass m (m < < M). When the car is at rest, the speed of transverse waves in the string is 60 ms$$-$$1. When the car has acceleration a, the wave-speed increases to 60.5 ms$$-$$1. The value of a, in terms of gravitational acceleration g, is closest to :
A
$${g \over {30}}$$
B
$${g \over 5}$$
C
$${g \over 10}$$
D
$${g \over 20}$$
3
JEE Main 2018 (Online) 16th April Morning Slot
+4
-1
Out of Syllabus
Two sitar strings, A and B, playing the note 'Dha' are slightly out of tune and produce beats of frequency 5 Hz. The tension of the string B s slightly increased and the beat frequency is found to decrease by 3Hz. If the frequency of A is 425 Hz, the original frequency of B is :
A
430 Hz
B
420 Hz
C
428 Hz
D
422 Hz
4
JEE Main 2018 (Online) 16th April Morning Slot
+4
-1
The end correction of a resonance column is 1 cm. If the shortest length resonating with the tunning fork is 10 cm, the next resonating length should be :
A
28 cm
B
32 cm
C
36 cm
D
40 c
EXAM MAP
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