Basic Physics Questions and Answers

The axle of a wheel rests in V grooves as shown in figure and string fixed to the rim of the wheel supported a mass M If u is the coefficient of friction W weight of wheel and axle a is the radius of the axle and b the radius of the wheel Then find the least value of M which will cause motion 1 1 T I

block of mass m is connected by three identical spring of force constants K K2 om its equilibrium position the time period of oscillation of the block is nd k3 as shown in the figure The block is given a small vertical displacement 2n 2T 0 m m K 1 B T 2 m K D 2 m 1 1 1 K K K3 ta wwwwwwwwwwww 5 k 5 mm E

19 Assertion In a system of co axial solenoids it is extremely difficult to calculate the flux linkage with the outer solenoid when current flows in inner solenoid Reason The magnetic field due to the inner solenoid would vary across the length as well as cross section of the outer solenoid when inner solenoid is smaller in length and radius

A bank deals with financial transactions and its related data belongs to an organization named XYZ Scenario 1 A transfers an amount of Rs 1000 to the account of XYZ Scenario 2 The account of XYZ did not receive Rs 1000 from A Which ACID property will be used to handle this scenario

4 18 An insulating rod of length carries a charge q uniformly distributed on it The rod is pivoted at one of its ends and is rotated at a frequency fabout a fixed perpendicular axis The magnetic moment of the rod is A C Rqfl 12 qfl B qfl 2 qfl

gh temperature 3 10 The density of hydrogen gas at STP is 0 9 kg m The mean kinetic energy of one gram molecule of UP CPMT 2015 d 3207 J for hydrogen gas is approx a 3403 T b 3500 J 1 A substance having coefficient S c 3704 J

Determine total value of impedance as series RLC circuit is shown below with total supply and frequency R 9022 U 100 V f 50 Hz C 10 F HH L 1 3 H

Department of Physics Amity Institute of Applied Sciences Amity University Uttar Pradesh Noida Applied Physics I 5 A diffraction grating is just able to resolve two line of 2 5140 and 5140 85 in the first order Will it resolve the line 8037 20 and 2 8037 50 A in the second order 6 The limits of visible spectrum are approximately 400nm and 700nm Find the angular width of the first order visible spectrum produced by a plane diffraction grating having 15000 lines per inches when the light is incident normally on the grating 7 What is the ratio of resolving powers of two gratings having 15000 lines in 2 cm and 10 000 lines in 1 cm in first order Each grating has lines in its 2 5 cm width 8 How many orders will be visible if the wavelength of incident radiation is 4800 and the number of lines on the grating is 25000 lines per inch 9 Light is incident normally on a grating of total ruled width 5 X 10 m with 2500 lines in all Calculate the angular separation of two sodium lines in the first order spectrum Can they be seen distinctly 10 The wavelengths of sodium D lines are 589 6nm and 589nm What is the minimum number of lines that a grating must have in order to resolve these lines in the first order spectrum 11 a What do you understand by the term resolving power of a grating Explain Rayleigh criterion for the limit of resolution b Two plane diffraction gratings A and B have the same width of ruled surface but on R Which has

c high pressure d high pressure and high temperature 0 The density of hydrogen gas at STP is 0 9 kg m 3 The mean kinetic energy of one gram molecule of hydrogen gas is approx a 3403 T b 3500 J c 3704 J UP CPMT 2015 d 3207 J itical expansion

period given arrangement shown in Fig 8 c Mass of disc rod sphere 10 10 12 kg respectively Disc Sphere m 2 m 4 m 3 m sc rod and sphere through as 5

When scattering of light is taking place and observer is observing at 90 scattered light will be A B Unpolarized Partially polarised Circularly polarised Perfectly plane polarised

in young s double slit experiment if source S is shifted by an angle as shown Then central bright fringe will be shifted by angl towards A 8 D end A of screen end B of screen does not shift at all S B either end A or B depending on extra phase difference caused by shifting of source

4 A football player kicks a ball at an angle of 30 to the horizontal with an initial velocity of 20 ms 1 Calculate i maximum height reached ii horizontal range of the football Given g ng 9 8 ms 2

In an ideal Atwood machine either side of pulley the sum of two masses is constant If the string can sustain a tension equal to 24 50 of the weight of the sum of the two masses then the least acceleration of the masses would be in 2 ms g 10ms O O 2 5 4

According to Maxwell light waves are associated with A a constant magnitude electric field a magnetic field of constant magnitude changing electric and magnetic fields electric and magnetic fields of constant magnitude

wo wattmeter method produces wattmeter readings P 1560 W and P 2100 W when connected to a delta connected load if the ine vollagers 220V a age power b the per phase reactive power c the power factor and d the phase impedance

A parallel plate capacitor is charged and disconnected If now the plates are pulled apart A The capacitance increases The potential difference increases The total charge increases The charge and potential difference remain the same

8 times the work A mass attached to a vertical spring causes the spring to stretch and the mass to move downwards What can you say about the spring s potential energy PEs and the gravitational potential energy PEg of the mass A both PES and PEg decrease B PEs increases and PEg decreases PEs increases and PEg is constant D PEs decreases and PEg increases C

this example we will find the position and magnification of an age formed by a spherical mirror A lamp is placed 10 cm in nt of a concave spherical mirror that forms an image of the ment on a screen placed 3 0 m from the mirror What is the dius of curvature of the mirror What is the lateral magnification he lamp filament is 5 0 mm high how tall is its image ure Screen Image Optic axis Object h 5 0 mm C HO 1 of 1 IS Mirror 10 cm KR P A concave mirror has a radius of curvature R 25cm An object of height 2 cm is placed 15 cm in front of the mirror What is the image distance Express your answers in centimeters to two significant figures VAZO Submit Request Answer Part B Practice Problem VAE Submit What is the height of the image Express your answer in centimeters to two significant figures Request Answer cm cm

A lawn roller is pulled along a horizontal surface through a distance of 20 m by a rope with a force of 200 N If the rope makes an angle of 60 with the vertical while pulling the amount of work done by the pulling force is 1 4000 1 2 1000 J

A disc of mass 4m and radius R is rotating freely with angular velocity wo 18 rad s about its axis which is fixed and vertical A small particle of mass m is placed at periphery of the disc gently and it starts rotating with disc then new angular speed of disc in rad s is

2 30 3 45 4 60 12 A block of mass m is in contact with the cart The coefficient of static friction between the block and the cart is u The acceleration a of the cart that prevent the block from falling will be 1 a 2 a 3 az g m mg 9 C o O a m

1 For a current carrying inductor the coefficient of mutual inductance is 100 mH If the current through it changes from 10 A to 2 A in 5 s then the emf in mV associated with it will be a 0 16 d 1 6 b 16 c 160

A conducting hollow spherical shell having inner radius a and outer radius b charge Q is given to this shell if a point charge q is placed at the centre of this sphere then what will be charge at inner surface and outer surface of hollow shell respectively

To provide electrical power to a residential area three phase transformers are connected in a star delta configuration Each single phase transformer is rated 10 KVA 15kV 240V What is the turn ratio 0 10 16 0 016 62 5

In a modified YDSE the region between screen and slits is immersed in a liquid whose refractive 5 until it 2 index varies with time as u 5 reaches a steady state value A glass plate of 3 thickness 36 m and refractive index is 2 S T 4 4 introduced infront of one of the slits What is speed of central maxima when it is at O S Hs g Y

In a setup of photoelectric experiment a light of intensity 384 W m2 is used which is equally distributed among three wavelengths 620 nm 496 nm and 310 nm The light is incident perpendiculary on a surface of area 0 01 cm2 having work function of 2 25 eV Assuming there is no loss of light and efficiency of emission of electrons from the surface is 50 The photocurrent in the circuit is 83 2 x 10 6 A 166 4 x 10 6 A 20 8 x 10 6 A 41 6 x 10 6 A

A particle is moving in x y plane such that sum of squares of both abscissa and ordinate is constant Locus of particle is A Straight line Circle Parabola D Hyperbola

2 A particle of mass mA m 2 moving along the z axis with velocity collides elastically with another particle B at rest having mass mg m 3 If both the to particles move along the x axis after the collision the change AA in the wavelength of the particle A in terms of its de Broglie wavelength Ao before the collision is A AA 20 B AA 40 D AA A C AX Ao

5 Match the C C ratio for ideal gases with different type of molecules Molecule Type A Monoatomic B Diatomic rigid molecules C Diatomic non rigid molecules D Triatomic rigid molecules 1 A III B IV C II D I 2 A IV B I C II D III 3 A IV B II C I D III 4 A II B III C I D IV Cp C 1 7 5 II 9 7 III 4 3 IV 5 3

b An aeroplane is flying in horizontal direction with a velocity of 540 km h and at a height of 2200 m A body is dropped from a point assume point A is the vertical projection on X axis and it strikes the ground at some another point assume B on X axis Calculate the distance AB and also find the velocity at B and time take to reach B

A constant volume gas thermometer using sulphur records a pressure of 2 x 104 Pa at the triple point of water and 2 87 104 Pa at temperature of melting sulphur Calculate the melting point of sulphur

2 A semi circular disc start rotating at t 0 with constant angular acceleration a 2 rad s2 about axis O as shown in figure Mass and radius of semicircular disc are 5 kg and 2x m respectively Magnitude or linear momentum of disc at t 3 s in kg m s is Do

A satellite of mass m is moving around a stationary planet of mass 10 m in an elliptical orbit of eccentricity e 1 3 and semi major axis a as shown in the figure Now choose the correct option s 10m m A 5Gm a The velocities of satellite at perihelion and aphelion are 2 The radius of curvature of the path of the satellite at perihelion is a The radius of curvature of the path of the satellite at perihelion is a Total time taken by the satellite in one complete revolution is 2 2 C and 5Gm a respectively

nonconducting The charges on two large parallel plates separated by a small distance are Q and Q A test charge q experiences a force F when placed between these plates Now if one of the plates is removed to infinity then the force on the test charge will become A F 2 B F C 2F D zero

If length and radius of cylinder is given by 5 0 0 1 cm and 2 00 0 01 cm then relative error in volume will be A B 0 03 C 0 02 D 0 01 0 04

Three equal masses of 3 kg are connected by two massless strings of cross sectional area 0 005 cm and Young modulus is 2 x 10 1 N m each The longitudinal strain in the wires A 3kg 3kg 1 are equal 2 cannot be different 3 must be different ay not be different B 3kg

I have a doubt that in Albert Einstein s theory it is there If a spaceship that is going at the 5 0 speed of light so the person in the space ship feels that for everyone time is very fast so if the spaceship goes to 99 at speed of I ight so the time for everyone will be even mo re faster and finaly the spaceship goes at th e speed of light so the time for everyone will stop so my question is why this happens and why the spaceship not stops as the time for t he people will stop and in 99 of speed of lig ht the time for people will faster and why not in the speed of light that happens

6 The work function of aluminium is 4 2 eV If two photons each of energy 3 5 eV strike an electron of aluminium then emission of electron will 7 a depend upon the density of the surface b possible c not possible d None of these A doubly ionised I i atom is excited from its around state n

3 C 4 Both A B The magnetic field B due to a solid cylindrical current carrying conductor varies with distance r from its axis as BA 1 O BA BA 2 O BA 3 O 4 Ok The angle of dip at a certain place where the ations

The sun radiates energy in all directions The average radiations received on the earth surface from the sun is 1 4 kilowatt m The average earth sun distance is 1 5x 10 1 meters The mass lost by the sun per day is 1 day 86400 seconds 1 4 4 10 kg 3 3 8 10 2 kg 2 7 6 10 4 kg 4 3 8 10 4 kg

A particle is acted by three forces as shown in the figure F F F B F a The resultant force on the particle may or may not be zero b The particle must be in rest e The direction of acceleration is in indeterminate form d The particle moves with variable velocity F

9 A square loop of side a is rotating in unifrom magnetic field B with angular frequency f such tha the direction of angular velocity is perpendicular to the magnetic field and along the plane of loop The average emf produced during half cycle is da doty 1 2 f a B 2 2 fa B 3 4 fa B 3 4 4 fa B

A current carrying loop is placed in a plane perpendicular to a long current carrying wire as shown 10 A Force on the loop is attractive B Force on the loop is repulsive C Force on the loop is zero only if loop is circular D Force on the loop is zero for any shape of loop

A gun crew observes a remotely controlled balloon launching an instrumented spy package in enemy territory When first noticed the balloon is at an altitude of 800 m and moving vertically upward at a constant velocity of 5 m s It is 1600 m down range Shells fired from the gun have an initial velocity of 400 m s at a fixed angle sine 3 5 and cos0 4 5 The gun crew waits and fires so as to destroy the balloon Assume g 10 m s Neglect air resistance Velocity of shell just before collision in ms is approximately 400m s 1600m Q1 15m s

Assume that the thermal conductivity of copper is twice that of aluminimum and four times that of brass Three metal rods made of copper aluminium and brass are each 15 cm long and 2 cm in diameter These rods are placed end to end with aluminium between the other two The free ends of the copper and brass rods are maintained at 100 C and 0 C respectively The system is allowed to reach the steady state condition Assume there is no loss of heat anywhere then More heat is transmitted across the copper aluminium junction than across the aluminium junction brass Equal amount of heat is transmitted at the copper aluminium and aluminium brass junctions Under steady state condition the equilibrium temperature of the copper aluminium junction will be 85 71 C

In the circuit shown assuming all ac ammeters to be ideal if readings of the ammeters A and A2 are i and is respectively then reading of the ammeter Asis 85666 AC source A equal to al B greater than

68 From NCER A circular ring of radius r is placed in a homogeneous magnetic field perpendicular to the plane of the ring The field B changes with time according to the equation B Kt where K is a constant and t is the time The electric field in the ring is 1 Kr 2 K Kr

Insibilisoo ad lliw bold p 8 no priggila zone 2 2m The system is pushed by Shyam applying a force F as shown in figure old 3 All surfaces are smooth except between B and C Friction coefficient between B and C is u Minimum value of F to prevent block B from downward slipping is 5 C A B 2 The minimum value of F if the friction coefficient A 3 2 mg mg B 2mg 11 mg C mg 2 0 3 D 2 between A and B is also is umg SY D D Fr mg 2 umg A 2m B m C 2m A M18 8

A substance is in the solid form at 0 C The amount of heat added to this substance and its temperature are plotted in the following graph If the relative specific heat capacity of the solid substance is 005 find from the grap The specific latent heat of the melting process in cal kg temp C 120 100 80 60 40 20 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 Q calories