CBSE
A siren emitting sound of frequency 800 Hz is going away from a static listener with a speed of 30 m/s. Frequency of the sound to be heard by the listener is (Take velocity of sound as 300 m/s)
733.3 Hz
481.2 Hz
644.8 Hz
286.5 Hz
Light propagates rectilinearly because of its
frequency
velocity
Wavelength
Wave nature
If equation of dound wave is y = 0.0015 sin ( 62.8 x + 316 t ) then its wavelength will be
0.2 unit
0.3 unit
0.1 unit
2 unit
Assertion: When a beetle moves along the sand within a few tens of centimetres of a sand scorpion, the scorpion immediately turns towards the beetle and dashes towards it.
Reason: When a beetle disturbs the sand, it sends pulses along the sand's surface. One set of pulses is longitudinal while the other set is transverse.
if both assertion and reason are true and the reason is the correct explanation of the assertion
if both assertion and reason are true and the reason is not the correct explanation of the assertion
if assertion and reason is false
if both assertion and reason are false statements
Assertion: The flash of lightening is seen before the sound of thunder is heard.
Reason: Speed of sound is greater than speed of light.
If both the assertion and reason are true and reason is a correct explanation of the assertion.
If both assertion and reason are true but assertion is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both assertion and reason are false.
The graph between wave number and angular frequency ( ω ) is
What is the path difference for destructive interference?
nλ
n ( λ + 1)
Two springs of force constants k and 2k are connected to a mass as shown in figure . The frequency of oscillation of the mass is
If fundamental frequency is 50 and next successive frequencies are 150 and 250 then it is
a pipe closed at both end
a pipe closed at one end
an open pipe
a stretched pipe
The Magnetic Resonance Imaging (MRI) is based on the phenomenon of
nuclear magnetic resonance
electron spin resonance
electron paramagnetic resonance
diamagnetism of human tissues