HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Important Questions

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}

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.

In Melde’s experiment, the number of loops on a string changes from 7 to 5 by the addition of 0.015 kgwt. Find the initial tension applied to the string.

Show that only odd harmonics are present in an air column vibrating in a pipe closed at one end.

A stretched wire emits a fundamental note of frequency 256 Hz. Keeping the stretching force constant and reducing the length of wire by 10 cm, the frequency becomes 320 Hz. Calculate the original length of wire.

Show the formation of stationary waves diagramatically

In the stationary wave, the distance between a node and its adjacent antinode is _______.

(a) λ

(b) `lambda/4`

(c) `lambda/2`

(d)  2λ

In Melde’s experiment, when the tension in the string is 10 g wt then three loops are obtained. Determine the tension in the string required to obtain four loops, if all other conditions are constant.

What is meant by harmonics?

Show that only odd harmonics are present as overtones in the case of an air column vibrating in a pipe closed at one end.

Assuming expression for impedance in a parallel resonant circuit, state the conditions for parallel resonance. Define resonant frequency and obtain an expression for it.

Show that even as well as odd harmonics are present as overtones in the case of an air column vibrating in a pipe open at both the ends.

A wheel of moment of inertia 1 kg.m² is rotating at a speed of 30 rad/s. Due to friction on the axis, it comes to rest in 10 minutes. Calculate the average torque of the friction.

A stretched sonometer wire is in unison with a tuning fork. When the length of the wire is increased by 5%, the number of beats heard per second is 10. Find the frequency of the tuning fork.

A sonometer wire 1 metre long weighing 2 g is in resonance with a tuning fork of frequency 300 Hz. Find tension in the sonometer wire.

Choose the correct option:

A parallel plate capacitor is charged and then isolated. The effect of increasing the plate separation on charge, potential, capacitance respectively are ______.

Answer in brief:

If the difference between the radii of the two spheres of a spherical capacitor is increased, state whether the capacitance will increase or decrease.

A dipole with its charges, - q and + q located at the points (O, -b, O) and (O, +b, O) is present in a uniform electric field E. The equipotential surfaces of this field are planes parallel to the yz plane.

(a) What is the direction of the electric field E?

(b) How much torque would the dipole experience in this field?

State law of length.

State law of linear density.