Date: October 2012

**Answer in brief:**

Derive an expression for the period of motion of a simple pendulum. On which factors does it depend?

Chapter: [0.04] Oscillations [0.05] Oscillations

A ballet dancer spins about a vertical axis at 2.5Π rad/s with his both arms outstretched. With the arms folded, the moment of inertia about the same axis of rotation changes by 25%. Calculate the new speed of rotation in r.p.m.

Chapter: [0.03] Angular Momentum

Discuss different modes of vibrations in an air column of a pipe open at both the ends.

Chapter: [0.06] Superposition of Waves [0.08] Stationary Waves

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.

Chapter: [0.06] Superposition of Waves [0.08] Stationary Waves

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.

Chapter: [0.02] Mechanical Properties of Fluids [0.06] Surface Tension

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/s^{2})

Chapter: [0.02] Mechanical Properties of Fluids [0.06] Surface Tension

Discuss the behaviour of wire under increasing load.

Chapter: [0.05] Elasticity

Derive an expression for one dimensional simple harmonic progressive wave travelling in the

direction of positive X-axis. Express it in ‘two’ different forms.

Chapter: [0.07] Wave Motion

The kinetic energy of nitrogen per unit mass at 300 K is 2.5 × 106 J/kg. Find the kinetic energy of 4 kg oxygen at 600 K. (Molecular weight of nitrogen = 28, Molecular weight of oxygen = 32)

Chapter: [0.04] Oscillations

A racing car completes 5 rounds of a circular track in 2 minutes. Find the radius of the track

if the car has uniform centripetal acceleration of Π^{2} m/s^{2}.

Chapter: [0.01] Circular Motion

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?

Chapter: [0.02] Mechanical Properties of Fluids [0.06] Surface Tension

Define radius of gyration

Chapter: [0.03] Angular Momentum

Explain the physical significance of radius of gyration

Chapter: [0.03] Angular Momentum

A body of mass 1 kg is made to oscillate on a spring of force constant 16 N/m. Calculate:

a) Angular frequency

b) frequency of vibration.

Chapter: [0.04] Oscillations

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

area.

Chapter: [0.02] Mechanical Properties of Fluids [0.06] Surface Tension

Show graphical representation of energy distribution spectrum of perfectly black body.

Chapter: [0.09] Kinetic Theory of Gases and Radiation

Explain black body radiation spectrum in terms of wavelength

Chapter: [0.09] Kinetic Theory of Gases and Radiation

‘g’ is the acceleration due to gravity on the surface of the Earth and ‘R’ is the radius of the

Earth.

Show that acceleration due to gravity at height ‘h’ above the surface of the Earth is

`gh = g (R/(R+H))^2`

Chapter: [0.02] Gravitation

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.

Chapter: [0.08] Stationary Waves

A planet is revolving around a star in a circular orbit of radius R with a period T. If the

gravitational force between the planet and the star is proportional to `R^(-3/2)` then

A) `T^2 prop R^(5/2)`

B) `T^2 prop R^((-7)/2)`

C) `T^2 prop R^(3/2)`

D) `T^2 prop R^4`

Chapter: [0.01] Circular Motion

If ‘L’ is the angular momentum and ‘I’ is the moment of inertia of a rotating body, then `L^2/(2I)`represents its _____

(A) rotational P.E.

(B) total energy

(C) rotational K.E.

(D) translational K.E

Chapter: [0.03] Angular Momentum

A particle executing linear S.H.M. has velocities v_{1} and v2 at distances x_{1} and x_{2} respectively from the mean position. The angular velocity of the particle is _______

`sqrt((x_1^2 - x_2^2)/(v_2^2 - v_1^2))`

`sqrt((v_2^2 - v_1^2)/(x_1^2 - x_2^2))`

`sqrt((x_1^2 + x_2^2)/(v_2^2 + v_1^2))`

`sqrt((v_2^2 + v_1^2)/(x_2^2 + x_1^2))`

Chapter: [0.04] Oscillations [0.05] Oscillations

A metal rod having coefficient of linear expansion (α) and Young’s modulus (Y) is heated to

raise the temperature by ΔΘ. The stress exerted by the rod is _______

A) `(Yα)/(ΔΘ)`

B) `(YΔΘ)/α`

C) YαΔΘ

D) `(αΔΘ)/Y`

Chapter: [0.05] Elasticity

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

Chapter: [0.02] Mechanical Properties of Fluids [0.06] Surface Tension

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.

Chapter: [0.06] Superposition of Waves [0.07] Wave Motion [0.1] Wave Theory of Light

The substance which allows heat radiations to pass through is _______.

(A) iron

(B) water vapour

(C) wood

(D) dry air

Chapter: [0.09] Kinetic Theory of Gases and Radiation

Obtain an expression for the induced e.m.f. in a coil rotating with uniform angular velocity in

uniform magnetic field. Plot a graph of variation of induced e.m.f. against phase (Θ = ωt) over one cycle.

Chapter: [0.16] Electromagnetic Inductions

The energy density at a point in a medium of dielectric constant 6 is 26.55 × 10^{6} J/m^{3}. Calculate electric field intensity at that point. (ε_{0} = 8.85 × 10^{−12} SI units).

Chapter: [0.12] Electrostatics

Write notes on Nuclear fission

Chapter: [0.18] Atoms, Molecules and Nuclei

Write notes on Nuclear fusion

Chapter: [0.18] Atoms, Molecules and Nuclei

A galvanometer has a resistance of 16Ω. It shows full scale deflection, when a current of 20 mA is passed through it. The only shunt resistance available is 0.06 which is not appropriate to convert a galvanometer into an ammeter. How much resistance should be connected in series with the coil of galvanometer, so that the range of ammeter is 8 A?

Chapter: [0.14] Magnetic Effects of Electric Current

Draw a well labelled diagram of photoelectric cell.

Chapter: [0.17] Electrons and Photons

Explain the observations made by Hertz and Lenard about the phenomenon of photoelectric

emission.

Chapter: [0.17] Electrons and Photons

Explain the working of transistor as a switch.

Chapter: [0.19] Semiconductors

The refractive indices of water for red and violet colours are 1.325 and 1.334 respectively.

Find the difference between the velocities of rays for these two colours in water. (c = 3 × 10^{8} m/s)

Chapter: [0.1] Wave Theory of Light

In Young’s experiment, the ratio of intensity at the maxima and minima in an interference

pattern is 36 : 9. What will be the ratio of the intensities of two interfering waves?

Chapter: [0.11] Interference and Diffraction

Explain the principle of potentiometer.

Chapter: [0.13] Current Electricity

Define Magnetic intensity.

Chapter: [0.15] Magnetism

What do you mean by polar molecules and non-polar molecules? Give ‘one’ example each.

Chapter: [0.18] Atoms, Molecules and Nuclei

The minimum angular separation between two stars is 4 × 10^{−6} rad, if telescope is used to observe them with an objective of aperture 16 cm. Find the wavelength of light used.

Chapter: [0.1] Wave Theory of Light

Explain the need for modulation related to the size of antenna (aerial).

Chapter: [0.2] Communication Systems

Four resistances 4Ω,8Ω,XΩ, and 6Ω are connected in a series so as to form Wheatstone’s

network. If the network is balanced, find the value of ‘X’.

Chapter: [0.09] Current Electricity [0.13] Current Electricity

The magnetic susceptibility of annealed iron at saturation is 4224. Find the permeability of

annealed iron at saturation. (μ_{0} = 4Π × 10^{−7} SI unit)

Chapter: [0.11] Magnetic Materials [0.15] Magnetism

A ray of light passes from a vacuum to a medium of refractive index (μ). The angle of

incidence is found to be twice the angle of refraction. The angle of incidence is _______.

A) `cos^(-1)(mu/2)`

B) cos^{−1}(μ)

C) `2 cos^(-1) (mu/2)`

D) `2 sin^(-1) (mu/2)`

Chapter: [0.1] Wave Theory of Light

The fringes produced in diffraction pattern are of _______.

(A) equal width with same intensity

(B) unequal width with varying intensity

(C) equal intensity\

(D) equal width with varying intensity

Chapter: [0.11] Interference and Diffraction

If ‘R’ is the radius of dees and ‘B’ be the magnetic field of induction in which positive charges (q) of mass (m) escape from the cyclotron, then its maximum speed (vmax) is _______.

A) `(qR)/(Bm)`

B)`(qm)/(Br)`

C) `(qBR)/m`

D) `m/(qBR)`

Chapter: [0.12] Electromagnetic Induction [0.16] Electromagnetic Inductions

The number of photoelectrons emitted _______.

(A) varies inversely with frequency

(B) varies directly with frequency

(C) varies inversely with intensity

(D) varies directly with intensity

Chapter: [0.17] Electrons and Photons

The width of depletion region of p-n junction diode is _______.

(A) 0.5 nm to 1 nm

(B) 5 nm to 10 nm

(C) 50 nm to 500 nm

(D) 500 nm to 1000 nm

Chapter: [0.19] Semiconductors

Any device that converts one form of energy into another is termed as ______.

(A) amplifier

(B) transducer

(C) receiver

(D) demodulator

Chapter: [0.2] Communication Systems

A transformer converts 240 V AC to 60 V AC. The secondary has 75 turns. The number of turns in primary are _______.

(A) 600

(B) 500

(C) 400

(D) 300

Chapter: [0.12] Electromagnetic Induction [0.16] Electromagnetic Inductions

#### Submit Question Paper

Help us maintain new question papers on Shaalaa.com, so we can continue to help studentsonly jpg, png and pdf files

## Maharashtra State Board previous year question papers 12th Board Exam Physics with solutions 2012 - 2013

Previous year Question paper for Maharashtra State Board 12th Board Exam Physics-2013 is solved by experts. Solved question papers gives you the chance to check yourself after your mock test.

By referring the question paper Solutions for Physics, you can scale your preparation level and work on your weak areas. It will also help the candidates in developing the time-management skills. Practice makes perfect, and there is no better way to practice than to attempt previous year question paper solutions of Maharashtra State Board 12th Board Exam.

How Maharashtra State Board 12th Board Exam Question Paper solutions Help Students ?

• Question paper solutions for Physics will helps students to prepare for exam.

• Question paper with answer will boost students confidence in exam time and also give you an idea About the important questions and topics to be prepared for the board exam.

• For finding solution of question papers no need to refer so multiple sources like textbook or guides.