HSC Science (General) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Answer in brief:

A string is fixed at the two ends and is vibrating in its fundamental mode. It is known that the two ends will be at rest. Apart from these, is there any position on the string which can be touched so as not to disturb the motion of the string? What will be the answer to this question if the string is vibrating in its first and second overtones? 

A photocell is used to automatically switch on the street lights in the evening when the sunlight is low in intensity. Thus it has to work with visible light. The material of the cathode of the photocell is ______.

If N_Red and N_Blue are the numbers of photons emitted by the respective sources of equal power and equal dimensions in unit time, then ______.

Choose the correct option.

The equation E = pc is valid ______.

A sonometer wire of length 0.5 m is stretched by a weight of 5 kg. The fundamental frequency of vibration is 100 Hz. Calculate the linear density of wire.

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. 

Answer in brief:

In a double-slit arrangement, the slits are separated by a distance equal to 100 times the wavelength of the light passing through the slits.

1. What is the angular separation in radians between the central maximum and an adjacent maximum?
2. What is the distance between these maxima on a screen 50.0 cm from the slits?

Answer in brief:

The distance between two consecutive bright fringes in a biprism experiment using the light of wavelength 6000 Å is 0.32 mm by how much will the distance change if light of wavelength 4800 Å is used?

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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.

Answer in brief:

A spherical shell of radius b with charge Q is expanded to a radius a. Find the work done by the electrical forces in the process.

In Young’s double-slit experiment, the two coherent sources have different intensities. If the ratio of the maximum intensity to the minimum intensity in the interference pattern produced is 25:1, what is the ratio of the intensities of the two sources?

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In Young's double-slit experiment, a thin uniform sheet of glass is kept in front of the two slits, parallel to the screen having the slits. The resulting interference pattern will satisfy:

White light consists of wavelengths from 400 nm to 700 nm. What will be the wavelength range seen when white light is passed through a glass of refractive index 1.55?

A parallel beam of green light of wavelength 550 nm passes through a slit of width 0.4 mm. The intensity pattern of the transmitted light is seen on a screen that is 40 cm away. What is the distance between the two first-order minima?

Monochromatic electromagnetic radiation from a distant source passes through a slit. The diffraction pattern is observed on a screen 2.50 m from the slit. If the width of the central maximum is 6.00 mm, what is the slit width if the wavelength is
(a) 500 nm (visible light)
(b) 50 µm (infrared radiation)
(c) 0.500 nm (X rays)?

Choose the correct:

Charge + q and - q are placed at points A and B respectively which are distance 2L apart. C is the midpoint of A and B. The work done in moving a charge + Q from C to D, along the semicircle CD as shown in the figure below, is ______.

The period of oscillation of a body of mass m₁ suspended from a light spring is T. When a body of mass m₂ is tied to the first body and the system is made to oscillate, the period is 2T. Compare the masses m₁ and m₂

A 20 cm wide thin circular disc of mass 200 g is suspended to rigid support from a thin metallic string. By holding the rim of the disc, the string is twisted through 60° and released. It now performs angular oscillations of period 1 second. Calculate the maximum restoring torque generated in the string under undamped conditions. (π³ ≈ 31)

Find the number of oscillations performed per minute by a magnet is vibrating in the plane of a uniform field of 1.6 × 10^-5 Wb/m². The magnet has a moment of inertia 3 × 10^-6 kg/m² and magnetic moment 3 A m².