HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Important Questions

The equation of simple harmonic progressive wave is given by `y=0.05sinpi[20t-x/6]` where all quantities are in S. I. units. Calculate the displacement of a particle at 5 m from origin and at the instant 0.1 second.

A wire of density ‘ρ’ and Young’s modulus ‘Y’ is stretched between two rigid supports separated by a distance ‘L’ under tension ‘T’. Derive an expression for its frequency in fundamental mode. Hence show that `n=1/(2L)sqrt((Yl)/(rhoL))` where symbols have their usual meanings

Let n₁ and n₂ be the two slightly different frequencies of two sound waves. The time interval between waxing and immediate next waning is ______.

(A) `1/(n_1-n_2)`

(B) `2/(n_1-n_2)`

(C) `(n_1-n_2)/2`

(D) `1/(2(n_1-n_2))`  

A sine wave of wavelength λ is travelling in a medium. What is the minimum distance between two particles of the medium which always have the same speed?

(A)`lambda`

(B)`lambda/2`

(C)`lambda/3`

(D)`lambda/4`

A transverse wave is produced on a stretched string 0.9 m long and fixed at its ends. Find the speed of the transverse wave, when the string vibrates while emitting the second overtone of frequency 324 Hz.

In Doppler effect of light, the term “red shift” is used for ______.

(A) frequency increase

(B) frequency decrease

(C) wavelength decrease

(D) frequency and wavelength increase

A set of 12 tuning forks is arranged in order of increasing frequencies. Each fork produces Y beats per second with the previous one. The last is an octave of the first. The fifth fork
has a frequency of 90 Hz. Find Y and frequency of the first and the last tuning forks.

Doppler effect is not applicable when _______.
(A) source and observer are at rest.
(B) there is a relative motion between source and observer.
(C) both are moving in opposite directions.
(D) both are moving in same direction with different velocities

The working of RADAR is based on ...............

a) resonance

b) speed of a star

c) Doppler effect

d) speed of rotation of sun

Derive an expression for one dimensional simple harmonic progressive wave travelling in the
direction of positive X-axis. Express it in ‘two’ different forms.

Apparent frequency of the sound heard by a listener is less than the actual frequency of sound emitted by source. In this case _______.

(A) listener moves towards source

(B) source moves towards listener

(C) listener moves away from the source.

(D) source and listener move towards each other.

State any four applications of Doppler effect

If the source is moving away from the observer, then the apparent frequency _____.

(a) will increase

(b) will remain the same

(c) will be zero

(d) will decrease

Explain the reflection of transverse and longitudinal waves from a denser medium and a rared medium.

Which of the following phenomenon proves that light is a transverse wave?

What are primary and secondary sources of light?

Why are multiple colours observed over a thin film of oil floating on water? Explain with the help of a diagram.

The optical path of a ray of light of a given wavelength travelling a distance of 3 cm in flint glass having refractive index 1.6 is the same as that on travelling a distance x cm through a medium having a refractive index 1.25. Determine the value of x. 

Describe Young's double-slit interference experiment and derive conditions for occurrence of dark and bright fringes on the screen. Define fringe width and derive a formula for it.

What are the conditions for obtaining a good interference pattern? Give reasons.