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

Two sound notes have wavelengths 83/170 m and 83/172 m in the air. These notes when sounded together produce 8 beats per second. Calculate the velocity of sound in the air and frequencies of the two notes.

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

Two soap bubbles have radii in the ratio 4:3. What is the ratio of work done to blow these bubbles?

Define surface tension and surface energy.

State the cause of end correction.

Find the end correction for the pipe open at both the ends in fundamental mode.

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

If two capillary tubes of different diameters are partially dipped in the same liquid vertically, then the rise of liquid ______.

A sonometer wire vibrates with three nodes and two antinodes, the corresponding mode of vibration is ...................

a) First overtone

b) Second overtone

c) Third overtane

d) Fourth overtone

Draw a neat labelled diagram of rise of liquid in capillary tube showing different components of tension (force).

A tube open at both ends has length 47 em. Calculate the fundamental frequency of air column. (Neglect end correction. Speed of sound in air is 3.3 x 10²m/s}

The total free surface energy of a liquid drop is `pisqrt2` times the surface tension of the liquid. Calculate the diameter of the drop in S.l. unit.

Draw neat labelled diagrams for modes of vibration of an air column in a pipe when it is closed at one end.

Hence derive an expression for fundamental frequency in each case.

A soap bubble of radius 12 cm is blown. Surface tension of soap solution is 30 dyne/cm. Calculate the work done in blowing the soap bubble.

In a conical pendulum, a string of length 120 cm is fixed at rigid support and carries a mass
of 150 g at its free end. If the mass is revolved in a horizontal circle of radius 0.2 m around a
vertical axis, calculate tension in the string (g = 9.8 m/s²)

A body weighs 4.0 kg-wt on the surface of the Earth. What will be its weight on the surface of a plant whose mass is `1/8` th of the mass of the Earth and radius half `(1/2)` of that of the Earth?

Show that the surface tension of a liquid is numerically equal to the surface energy per unit
area.

A big drop of radius R is formed from 1000 droplets of water. The radius of a droplet will be _______

A) 10 R

B) R/10

C) R/100

D) R/1000

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.