If the pressure of an ideal gas decreases by 10% isothermally, then its volume will _______.

(A) decrease by 9%

(B) increase by 7%

(C) increase by 10%

(D) increase by 11.4%

Concept: Derivation for Pressure of a Gas

Stretching of a rubber band results in _______.

(A) no change in potential energy.

(B) zero value of potential energy.

(C) increase in potential energy.

(D) decrease in potential energy.

Concept: Elastic Energy

When the angular acceleration of a rotating body is zero, which physical quantity will be equal to zero?

(A) Angular momentum

(B) Moment of inertia

(C) Torque

(D) Radius of gyration

Concept: Angular Acceleration

In a damped harmonic oscillator, periodic oscillations have _______ amplitude.

(A) gradually increasing

(B) suddenly increasing

(C) suddenly decreasing

(D) gradually decreasing

Concept: Simple Harmonic Motion

A sine wave of wavelength λ is travelling in a medium. What is the minimum distance between two particles of the medium which always have the same speed?

(A)`lambda`

(B)`lambda/2`

(C)`lambda/3`

(D)`lambda/4`

Concept: Simple Harmonic Progressive Waves,

Velocity of transverse wave along a stretched string is proportional to _______. (T = tension

in the string)

(A) `sqrtT`

(B) `T`

(C) `1/sqrtT`

(D) `1/T`

Concept: Definition of Stress and Strain

Find the wavelength at which a black body radiates maximum energy, if its temperature is 427°C.

(Wein’s constant b = 2.898 × 10^{-3} mK)

(A) 0.0414 × 10^{-6}m

(B) 4.14 × 10^{-6}m

(C) 41.4 × 10^{-6}m

(D) 414 × 10^{-6}m

Concept: Qualitative Ideas of Blackbody Radiation

Explain the concept of centripetal force.

Concept: Dynamics of Uniform Circular Motion - Centripetal Force

Prove that root mean square velocity of gas molecule is directly proportional to the square root of its absolute temperature.

Concept: Kinetic Theory of Gases- Assumptions

Obtain the differential equation of linear simple harmonic motion.

Concept: Differential Equation of Linear S.H.M.

Draw a neat, labelled diagram for a liquid surface in contact with a solid, when the angle of contact is acute.

Concept: Capillarity and Capillary Action

A hole is drilled half way to the centre of the Earth. A body is dropped into the hole. How much will it weigh at the bottom of the hole if the weight of the body on the Earth’s surface is 350 N?

Concept: Acceleration Due to Gravity and Its Variation with Altitude and Depth

A solid sphere of mass 1 kg rolls on a table with linear speed 2 m/s, find its total kinetic energy.

Concept: Rolling Motion

A transverse wave is produced on a stretched string 0.9 m long and fixed at its ends. Find the speed of the transverse wave, when the string vibrates while emitting second overtone of frequency 324 Hz.

Concept: Reflection of Transverse and Longitudinal Waves

A body cools at the rate of 0.5°C / minute when it is 25° C above the surroundings. Calculate the rate of cooling when it is 15°C above the same surroundings.

Concept: Derivation of Boyle’s Law

Show that period of a satellite revolving around the Earth depends upon mass of the Earth.

Concept: Projection of Satellite

Obtain an expression for torque acting on a rotating body with constant angular acceleration. Hence state the dimensions and SI unit of torque.

Concept: Torque and Angular Momentum

The total energy of free surface of a liquid drop is 2π times the surface tension of the liquid. What is the diameter of the drop? (Assume all terms in SI unit).

Concept: Surface Tension

A vehicle is moving on a circular track whose surface is inclined towards the horizon at an angle of 10°. The maximum velocity with which it can move safely is 36 km / hr. Calculate the length of the circular track. [π = 3.142]

Concept: Uniform Circular Motion

Prove the law of conservation of energy for a particle performing simple harmonic motion.Hence graphically show the variation of kinetic energy and potential energy w. r. t.instantaneous displacement.

Concept: K.E.(Kinetic Energy) and P.E.(Potential Energy) in S.H.M.

Two sound notes have wavelengths 83/170 m and 83/172 m in the air. These notes when sounded together produce 8 beats per second. Calculate the velocity of sound in the air and frequencies of the two notes.

Concept: Study of Vibrations of Air Columns

Explain analytically how the stationary waves are formed

Concept: Formation of Stationary Waves on String

Show the formation of stationary waves diagramatically

Concept: Formation of Stationary Waves on String

A mass of 1 kg is hung from a steel wire if radius 0.5 mm and length 4 m. Calculate the extension produced. What should be the area of cross-section of the wire so that elastic limit is not exceeded? Change in radius is negligible

(Given : g = 9.8 m/s^{2;} Elastic limit of steel is 2.4 x 10^{8} N/m^{2};Y for steel (Ysteel) = 20 x 10^{10} N/m^{2}; π = 3.142)

Concept: Behaviour of Metal Wire Under Increasing Load

If A.C. voltage is applied to a pure capacitor, then voltage across the capacitor ______.

(A) leads the current by phase angle (π/2) rad.

(B) leads the current by phase angle π rad.

(C) lags behind the current by phase angle (π/2) rad.

(D) lags behind the current by phase angle π rad.

Concept: Inductance and Capacitance

In Doppler effect of light, the term “red shift” is used for ______.

(A) frequency increase

(B) frequency decrease

(C) wavelength decrease

(D) frequency and wavelength increase

Concept: Beats

If a watch-glass containing a small quantity of water is placed on two dissimilar magnetic poles, then water ______.

(A) shows a depression in the middle.

(B) shows an elevation in the middle.

(C) surface remains horizontal.

(D) evaporates immediately.

Concept: Motion in Combined Electric and Magnetic Fields - Cyclotron

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

(A) amplifier

(B) transducer

(C) receiver

(D) demodulator

Concept: Elements of a Communication System

When a p-n-p transistor is operated in saturation region, then its ______.

(A) base-emitter junction is forward biased and base-collector junction is reverse biased.

(B) both base-emitter and base-collector junctions are reverse biased.

(C) both base-emitter and base-collector junctions are forward biased.

(D) base-emitter junction is reverse biased and base-collector junction is forward biased

Concept: Transistor and Characteristics of a Transistor

In a photon-electron collision ______.

(A) only total energy is conserved.

(B) only total momentum is conserved.

(C) both total energy and total momentum are conserved.

(D) both total momentum and total energy are not conserved

Concept: Nuclear Energy - Nuclear Fusion – Energy Generation in Stars

If the charge on the condenser of 10°F is doubled, then the energy stored in it becomes

(A) zero

(B) twice that of initial energy

(C) half the initial energy

(D) four times the initial energy

Concept: Energy Bands in Solids

Distinguish between the phenomenon of interference and diffraction of light.

Concept: Interference of Light

Explain how moving coil galvanometer is converted into a voltmeter. Derive the necessary formula.

Concept: Moving Coil Galvanometer

State the advantages of potentiometer over voltmeter.

Concept: Metre Bridge

Draw a neat, labelled block diagram of a receiver for the detection of amplitude modulated wave.

Concept: Elements of a Communication System

A rectangular coil of a moving coil galvanometer contains 100 turns, each having area

15 cm^{2}. It is suspended in the radial magnetic field 0.03 T. The twist constant of suspension

fibre is 15 x 10^{-10} N-m/degree. Calculate the sensitivity of the moving coil galvanometer.

Concept: Moving Coil Galvanometer

The magnetic flux through a loop is varying according to a relation `phi = 6t^2 + 7t + 1` where `phi` is in milliweber and t is in second. What is the e.m.f. induced in the loop at t = 2 second?

Concept: Electromagnetic Induction

An unknown resistance is placed in the left gap and resistance of 50 ohm is placed in the right gap of a meter bridge. The null point is obtained at 40 cm from the left end. Determine the unknown resistance.

Concept: Meter Bridge

Find the frequency of revolution of an electron in Bohr’s 2nd orbit; if the radius and speed of electron in that orbit is 2.14 × 10^{-10} m and 1.09 × 10^{6} m/s respectively. [π= 3.142]

Concept: Bohr'S Model for Hydrogen Atom

With the help of neat labelled circuit diagram explain the working of half wave rectifier using semiconductor diode. Draw the input and output waveforms.

Concept: Semiconductor Diode

Explain self induction and mutual induction

Concept: Inductance - Mutual Inductance

A cube of marble having each side 1 cm is kept in an electric field of intensity 300 V/m. Determine the energy contained in the cube of dielectric constant 8. [Given : ∈_{0} = 8.85 10^{–12} C^2/Nm^2]

Concept: Energy of Charged Condenser

An electron in an atom revolves around the nucleus in an orbit of radius 0.53 Å. If the frequency of revolution of an electron is 9 x10^{9} MHz, calculate the orbital angular momentum

[Given : Charge on an electron = 1.6 x 10^{–19} C; Gyromagnetic ratio = 8.8 x 10^{10} C/kg; π = 3.142]

Concept: Magnetic Dipole Moment of a Revolving Electron

Describe biprism experiment to calculate the wavelength of a monochormatic light. Draw the necessary ray diagram.

Concept: Measurement of Wavelength by Biprism Experiment

The width of plane incident wavefront is found to be doubled on refraction in denser medium. If it makes an angle of 65° medium. with the normal, calculate the refractive index for the denser medium.

Concept: Measurement of Wavelength by Biprism Experiment

Draw a neat, labelled energy level diagram for H atom showing the transitions. Explain the series of spectral lines for H atom, whose fixed inner orbit numbers are 3 and 4 respectively.

Concept: Bohr'S Model for Hydrogen Atom

The work functions for potassium and caesium are 2.25 eV and 2.14 eV respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 Å?

[Given : Planck’s constant = 6.63 x 10^{–34} J.s.;

Velocity of light = 3 x 10^{8} m/s; 1 eV = 1.6 x 10^{–19} J]

Concept: Photoelectric Effect - Hertz’S Observations