HSC Science (Electronics) 12th Board ExamMaharashtra State Board
Account
It's free!

Share

Books Shortlist

# Question Paper Solutions - Physics 2013 - 2014 HSC Science (Electronics) 12th Board Exam

SubjectPhysics
Year2013 - 2014 (October)

Marks: 70
[9]1 | Attempt any THREE
[3]1.1

Draw a diagram showing all components of forces acting on a vehicle moving on a curved banked road.

Chapter: [1] Circular Motion

Write the necessary equation for maximum safety, speed and state the significance of each term involved in it.

Chapter: [1] Circular Motion
[3]1.2

Explain Maxwell distribution of molecular speed with necessary graph.

Chapter: [9] Kinetic Theory of Gases and Radiation
Concept: Maxwell Distribution
[3]1.3

Find the total energy and binding energy of an artificial satellite of mass 800 kg orbiting at a height of 1800 km above the surface of the earth.

[G = 6.67 x 10-11 S.I. units, Radius of earth : R = 6400 km, Mass of earth : M = 6 x 1024 kg]

Chapter: [2] Gravitation
Concept: Binding Energy and Escape Velocity of a Satellite
[3]1.4

Wavelengths of two notes in the air are[70/153]^m and [70/157]^m. Each of  these notes produces 8 beats per second with a tuning fork of fixed frequency. Find the velocity of sound in the air and frequency of the tuning fork.

Chapter: [7] Wave Motion
Concept: Beats

Wavelengths of two notes in the air are[70/153]^m and [70/157]^m. Each of  these notes produces 8 beats per second with a tuning fork of fixed frequency. Find the velocity of sound in the air and frequency of the tuning fork.

Chapter: [10] Wave Theory of Light
Concept: Beats
[12]2 | Attempt any SIX
[2]2.1

Draw a diagram showing different stages of projection for artificial satellite.

Chapter: [2] Gravitation
Concept: Projection of Satellite
[2]2.2

State the law of conservation of angular momentum and explain with a suitable example.

Chapter: [3] Angular Momentum
Concept: Torque and Angular Momentum
[2]2.3

Define the angle of contact.

Chapter: [6] Surface Tension
Concept: Surface Tension

State any two characteristics of the angle of contact

Chapter: [6] Surface Tension
Concept: Surface Tension
[2]2.4

Draw a neat labelled diagram for Ferry's perfectly black body.

Chapter: [9] Kinetic Theory of Gases and Radiation
Concept: Qualitative Ideas of Blackbody Radiation
[2]2.5

A stone of mass 5 kg. tied to one end of a rope of length 0.8 m, is whirled in a vertical circle. Find the minimum velocity at the highest point and at the midway point.

[g = 9.8 m/s2]

Chapter: [1] Circular Motion
Concept: Equation for Velocity and Energy at Different Positions of Vertical Circular Motion
[2]2.6

The maximum velocity of a particle performing linear S.H.M. is 0.16 m/s. If its maximum acceleration is 0.64 m/s2, calculate its period.

Chapter: [4] Oscillations
Concept: Differential Equation of Linear S.H.M.
[2]2.7

Water rises to a height 3.2 cm in a glass capillary tube. Find the height to which the same water will rise in another glass capillary having half area of cross section.

Chapter: [6] Surface Tension
Concept: Surface Tension
[2]2.8

A 36 cm long sonometer wire vibrates with frequency of 280 Hz in fundamental mode, when it is under tension of 24.5 N. Calculate linear density of the material of wire.

Chapter: [12] Electrostatics
Concept: Applications of Gauss’s Law
[7]3 | Select and write the most appropriate answer from the given alternatives for each sub-question
[1]3.1

A thin wire of length L and uniform linear mass density r is bent into a circular coil. M. I. of the coil about tangential axis in its plane is ................................

1. (3rhoL^2)/(8pi^2)
2. (8pi^2)/(3rhoL^2)
3. (3rhoL^3)/(8pi^2)
4. (8pi^2)/(3rhoL^3)

Chapter: [3] Angular Momentum
Concept: Physical Significance of M.I (Moment of Inertia)
[1]3.2

The average displacement over a period of S.H.M. is ....................................

(A = amplitude of S.H.M.)

1. 0
2. A
3. 2A
4. 4A
Chapter: [4] Oscillations
Concept: Simple Harmonic Motion
[1]3.3

In which of the following substances, surface tension increases with increase in temperature ?

1. Copper
2. Molten copper
3. Iron
4. Molten iron
Chapter: [6] Surface Tension
Concept: Surface Tension
[1]3.4

The ratio of diameters of two wires of the same material and length is n : 1. If the same load is applied to both the wires then increases in the length of the thin wire is ........................ (n > 1).

1. n1/4 times
2. n1/2 times
3. n times
4. n2 times
Chapter: [5] Elasticity
Concept: Behaviour of Metal Wire Under Increasing Load
[1]3.5

The co-efficient of reflection of an opaque body is 0.16. Its co-efficient of emission is ........................................

1. 0.94
2. 0.84
3. 0.74
4. 0.64
Chapter: [11] Interference and Diffraction
Concept: Interference of Light
[1]3.6

Let velocity of a sound wave be 'v' and 'ω' be angular velocity. The propagation constant of the wave is .................................

1. sqrt(omega/v)
2. sqrt(v/omega)
3. omega/v
4. v/omega
Chapter: [1] Circular Motion
Concept: Equation for Velocity and Energy at Different Positions of Vertical Circular Motion
[1]3.7

The value of end correction for an open organ pipe of radius 'r' is .........................

A) 0.3 r

B) 0.6 r

C) 0.9 r

D) 1.2 r

Chapter: [8] Stationary Waves
Concept: Study of Vibrations of Air Columns
[7]4 | Attempt any ONE
[7]4.1

Distinguish between forced vibrations and resonance.

Chapter: [8] Stationary Waves
Concept: Free and Forced Vibrations

Draw neat, labelled diagrams for the modes of vibration of a stretched string in second harmonic and third harmonic.

Chapter: [8] Stationary Waves
Concept: Study of Vibrations in a Finite Medium

The area of the upper face of a rectangular block is 0.5 m by 0.5 m and the lower face is fixed. The height of the block is 1 cm. A shearing force applied at the top face produces a displacement of 0.015 mm. Find the strain and shearing force.

(Modulus of rigidity: η = 4.5 x 1010 N/m2)

Chapter: [5] Elasticity
Concept: Definition of Stress and Strain
[7]4.2

Define phase of S.H.M.

Chapter: [4] Oscillations
Concept: Simple Harmonic Motion

Show variation of displacement, velocity, and acceleration with phase for a particle performing linear S.H.M. graphically, when it starts from the extreme position.

Chapter: [4] Oscillations
Concept: Simple Harmonic Motion

A body starts rotating from rest. Due to a couple of 20 Nm it completes 60 revolutions in one minute. Find the moment of inertia of the body.

Chapter: [3] Angular Momentum
Concept: Physical Significance of M.I (Moment of Inertia)
[9]5 | Attempt any THREE
[3]5.1

In a biprism experiment, a slit is illuminated by a light of wavelength 4800 Å The distance between the slit and biprism is 15 cm and the distance between the biprism and eyepiece is 85 cm. If the distance between virtual sources is 3 mm, determine the distance between 4th bright band on one side and 4th dark band on the other side of the central bright band.

Chapter: [11] Interference and Diffraction
Concept: Measurement of Wavelength by Biprism Experiment
[3]5.2

Six capacitors of capacities 5, 5. 5, 5, 10 and X μ F are connected as shown in the network in the diagram.

Find :

1. The value of X if the network is balanced, and
2. The resultant capacitance between A and C.

Chapter: [16] Electromagnetic Inductions
Concept: Inductance and Capacitance
[3]5.3

Show that the current flowing through a moving coil galvanometer is directly proportional to the angle of deflection of coil.

Chapter: [14] Magnetic Effects of Electric Current
Concept: Moving Coil Galvanometer
[3]5.4

Explain the formation of energy band diagram in case of conductor and semiconductor.

Chapter: [19] Semiconductors
Concept: Energy Bands in Solids
[12]6 | Attempt any SIX
[2]6.1

Draw a neat labelled diagram showing the plane of vibration and plane of polarisation for polarised light.

Chapter: [10] Wave Theory of Light
Concept: Polarisation
[2]6.2

State the conditions to get steady interference pattern.

Chapter: [11] Interference and Diffraction
Concept: Interference of Light
[2]6.3

In a hydrogen atom, an electron carrying charge 'e' revolves in an orbit of radius 'r' with speed 'v'. Obtain an expression for the magnitude of magnetic moment of a revolving electron.

Chapter: [15] Magnetism
Concept: Current Loop as a Magnetic Dipole and Its Magnetic Dipole Moment
[2]6.4

Draw a neat, labelled block diagram for a generalised communication system.

Chapter: [20] Communication Systems
Concept: Elements of a Communication System
[2]6.5

A red light of wavelength 6400A° in air has wavelength 4000A° in glass. If the wavelength of violet light in air is 4400A°, find its wavelength in glass.

(Assume that μ≈ μv)

Chapter: [11] Interference and Diffraction
Concept: Measurement of Wavelength by Biprism Experiment
[2]6.6

The magnetic moment of a magnet of dimensions 5 cm × 2.5 cm × 1.25 cm is 3 Am2. Calculate the intensity of magnetization.

Chapter: [15] Magnetism
Concept: Magnetisation and Magnetic Intensity
[2]6.7

An A.C. circuit consists of inductor of inductance 125 mH connected in parallel with a capacitor of capacity 50 μF. Determine the resonant frequency.

Chapter: [16] Electromagnetic Inductions
Concept: Resonant Circuit
[2]6.8

Calculate the de Broglie wavelength of an electron moving with - of the speed of light in vacuum (Negelct relativistic effect)

(Planck's constant: h = 6.63 x 10-34 Js, Mass of electron : m = 9.11 x 10-28 g)

Chapter: [18] Atoms, Molecules and Nuclei
Concept: de-Broglie Relation
[7]7 | Select and write the most appropriate answer from the given alternatives for each sub-question
[1]7.1

If numerical aperture of a microscope is increased, then its .......................................... .

1. resolving power decreases
2. limit of resolution decreases
3. resolving power remains constant
4. limit of resolution increases.
Chapter: [11] Interference and Diffraction
Concept: Resolving Power of a Microscope and Telescope
[1]7.2

A solenoid of length 1.5 m and 4 cm in diameter possesses 10 turns per metre. A current of 5 A is flowing through it. The magnetic induction at a point inside the solenoid along the axis is ............................. .

0 = 4π × 10-7 Wb/Am)

1. π  × 10-5 T
2. 2π × 10-5 T
3. 3π × 10-5 T
4. 4π × 10-5 T
Chapter: [16] Electromagnetic Inductions
Concept: Electromagnetic Induction
[1]7.3

Kirchhoff's voltage law and current law are respectively in accordance with the conservation of .................................. .

1. charge and momentum
2. charge and energy
3. energy and charge
4. energy and momentum
Chapter: [13] Current Electricity
Concept: Kirchhoff’s Rules
[1]7.4

When radiations of wavelength λ1 and λ2 are incident on certain photosensitive, such that E1 > E2 . Then Planck's constant 'h' is ......................... .

(C = Velocity of light).

1. ((E_1 - E_2)(lambda_1 - lambda_2))/(C(lambda_1 * lambda_2))
2. ((E_1 - E_2)lambda_1C)/((lambda_1 - lambda_2)lambda_2)
3. ((E_1 - E_2)lambda_1lambda_2)/(C(lambda_2 - lambda_1))
4. ((lambda_1 - lambda_2)C)/((E_1 - E_2)lambda_1 * lambda_2)
Chapter: [17] Electrons and Photons
Concept: Einstein’s Equation - Particle Nature of Light
[1]7.5

Colour of light emitted by LED depends upon__________________ .

1. its forward bias
2. its reverse bias
3. the band gap of the material of semiconductor
4. its size
Chapter: [19] Semiconductors
Concept: Special Purpose P-n Junction Diodes
[1]7.6

Line of sight propagation is also called as_________________ .

1. sky wave
2. ground wave
3. sound wave
4. space wave
Chapter: [20] Communication Systems
Concept: Propagation of Electromagnetic Waves
[1]7.7

Two parallel plates separated by distance d are kept at potential difference V volt. A charge q of mass m enters in parallel plates with some velocity. The acceleration of the charged particle will be_____________________________ .

1. q V/d m
2. d m/ q V
3. q m/d V
4. d V/q m
Chapter: [1] Circular Motion
Concept: Angular Acceleration
[7]8 | Attempt any ONE
[7]8.1

Explain the phenomenon of self induction

Chapter: [16] Electromagnetic Inductions
Concept: Inductance - Self-Inductance

Explain the phenomenon of mutual induction.

Chapter: [16] Electromagnetic Inductions
Concept: Inductance - Mutual Inductance

Define coefficient of self induction.

Chapter: [16] Electromagnetic Inductions
Concept: Inductance - Self-Inductance

Define coefficient of mutual induction.

Chapter: [16] Electromagnetic Inductions
Concept: Inductance - Mutual Inductance

Write the SI unit and dimention of of co-efficient of self induction

Chapter: [16] Electromagnetic Inductions
Concept: Inductance - Self-Inductance

A potentiometer wire has a length of 4 m and a resistance of 5 Ω. What resistance should be connected in series with a potentiometer wire and a cell of e.m.f. 2 V having internal resistance 1 Ω to get a potential gradient of 10-3 V/cm ?

Chapter: [13] Current Electricity
Concept: Metre Bridge
[7]8.2

Derive an expression for the total energy of electron in ‘n' th Bohr orbit. Hence show that energy of the electron is inversely proportional to the square of principal quantum number. Also define binding energy.

Chapter: [18] Atoms, Molecules and Nuclei
Concept: Mass-energy and Nuclear Binding Energy - Nuclear Binding Energy

The photoelectric threshold wavelength of a metal is 230 nm. Determine the maximum kinetic energy in joule and in eV of the ejects electron for the metal surface when it is exposed to a radiation of wavelength 180 nm.

[Planck’s constant : h = 6.63 * 10-34 Js, Velocity of light : C = 3 * 108 m/s.]

Chapter: [17] Electrons and Photons
Concept: Einstein’s Equation - Particle Nature of Light
S