Physics 2013-2014 HSC Science (General) 12th Standard Board Exam Question Paper Solution

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

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

Explain Maxwell distribution of molecular speed with necessary graph.

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]

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.

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

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

Define the angle of contact.

State any two characteristics of the angle of contact

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

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]

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.

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.

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.

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)`

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

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

0

A

2A

4A

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

1. Copper
2. Molten copper
3. Iron
4. Molten iron

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. n^1/4 times
2. n^1/2 times
3. n times
4. n² times

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

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`

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

Distinguish between forced vibrations and resonance.

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

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)

Define phase of S.H.M.

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.

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.

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.

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.

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

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

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

State the conditions to get steady interference pattern.

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.

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

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_r ≈ μ_v)

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

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.

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)

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

resolving power decreases

limit of resolution decreases

resolving power remains constant

limit of resolution increases

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 ............................. .

(μ₀ = 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

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

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).

`((E_1 - E_2)(lambda_1 - lambda_2))/(C(lambda_1 * lambda_2))`

`((E_1 - E_2)lambda_1C)/((lambda_1 - lambda_2)lambda_2)`

`((E_1 - E_2)lambda_1lambda_2)/(C(lambda_2 - lambda_1))`

`((lambda_1 - lambda_2)C)/((E_1 - E_2)lambda_1 * lambda_2)`

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

Line of sight propagation is also called as_________________ .

sky wave

ground wave

sound wave

space wave

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

Explain the phenomenon of self induction

Explain the phenomenon of mutual induction.

Define the coefficient of self-induction.

Define coefficient of mutual induction. 

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

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 ?

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.

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.]