Physics Questions

4 4 points The height of a ball dropped from the top of a building 224 feet high is given by h t 16t 224 where t is in seconds and his in feet a When will the ball reach the ground Approximate your answer to two decimal places Hint The height is 0 when it hits the ground b Why can t only be a positive value Explain in a complete sentence

The block in Fig 2 of mass m is pressed against the ideal spring of elastic constant k and compresses it by a distance d The block is released and ascends the inclined plane whose angle of inclination is 8 The coefficient of kinetic friction between the block and the plane is u What maximum height h does the block rise in the plane Express h as a function of m k d 0 and g Do the free body diagram k m u h

and at an 1 A projectile is launched with angle 0 with the horizontal The rate of change of speed and radius of curvature respectively at the highest point are 1 9 v sin 20 2g 2 Zero 3 Zero TAX v sin 20 g v cos 0 29 v cos 0 Zero B x H Zainzo g

84 In the figure shown the rod is uniform and has a mass m length L The horizontal thread is conner rod at a point at a distance L 3 along the rod from lower end and angle between rod and wall is 60 V A In equilibrium tension in the thread is 3mg 2 B In equilibrium tension in the thread is 3 3mg 2 150 25 C The minimum value of friction coefficient between the lower end of rod and the vertical wall for the rod be in equilibrium is 2 3 3 D The maximum value of friction coefficient between the lower end of rod and the vertical wall for the

Which of the following sets of vectors given below may have zerc resultant 12 14 28 14 18 36 O 11 22 17

Calculate the moment of inertia of a disc of mass 0 4Kg and radius 0 12m about an axis passing through its center and at right angles to its plane What would be the moment of inertia if the axis passes through a point at a distance from the center equal to half the radius of the disc

81 Two waves of wavelengths and 2 A2 produce 6 beats sa 51 per second If M 9 find the speed of sound wave 2 in a gas in which these waves produce beats a 316 m s b 310 m s c 306 m s d 326 m s

P In the circuit shown R R 10 0 and resistance per unit length of wire PQ 10 cm and length PQ 10 cm If R is made 200 then to get zero deflection in galvanometer S is midpoint of wire PQ R RI 12VT S Q The jockey at P can be moved towards right 3 cm The jockey at Q can be moved towards left 2 cm The jockey at S can be moved towards left a distance 5 3 cm

One day in the morning Ramesh filled up 1 3 bucket of hot water from geyser to take bath Remaining 2 3 was to be filled by cold water at room temperature to bring mixture to a comfortable temperature Suddenly Ramesh had to attend to something which would take some times say 5 10 minutes before he could take bath Now he had two options i fill the remaining bucket completely by cold water and then attend to the work ii first attend to the work and fill the remaining bucket just before taking bath Which option do you think would have kept water warmer Explain

An observer at distance r from point source observes intensity at decibal scale B dB Now eight coherent identical point source all are in same phase are placed at the position of previous source and observer move to a distance 3r from sources log 2 0 3 logic 3 0 47 Ratio of intensity from eight sources at distance 3r to the intensity due to one source at distance ris

A current of 10 A is passing through an aluminium wire of cross sectional area 4x10 m The density of the aluminium conductor is 2 7 g cc Considering aluminium gives 1 electron per atom for conduction then find the drift velocity of the electrons if molecular weight of aluminium is 27 g a 1 6 x 10 b 3 6 x 10 c 2 6 x 10 d 1 5x 10 m s m s m s m s

Estimate how long it might take for ethyl alcohol to be detected 6 cm from a bottle after it opened assuming only diffusion is occurring Assume the diffusion constant is 10 5 m 2 s Select one 45 s O 3 min 4 5 s O 0 18 s

A stone of mass 1kg tied to a light 10 inextensible string of length L 3m is whirling in a circular path of radius L in a vertical plane If the ratio of the maximum tension is the string to the minimum tension in the string is 4 and g 10 m s The speed of stone at the highest point of the circle is 1 20 m s 2 10 3 m s 3 5 2 m s 4 10 m s

0 2 mA oltage is fed to the amplifier with common emitter configuration as given by the equati Vin Vo sin 145t where t is time The output voltage from the amplifier may be Vin Vosin 1957 1 Vout Vo sin 145t 7 3 Vout Vo sin 145t 6 2 Vout Vo sin 145t x T 4 Vout Vo sin 145t

9 The electric potential V at any point x y all in metres in space is given by V 4x volt The electric field at the point 1 m 0 2 m in volt metre is a 8 along negative X axis c 16 along negative X axis b 8 along positive X axis d 16 along positive Z axis

or j oE where o 1 p is called the conductivity Ohm s law is often stated in an equivalent form Eq 3 13 in addition to Eq 3 3 In the next section we will try to understand the origin of the Ohm s law as arising from the characteristics of the drift of electrons

27 During an adiabatic process the pressure of a gas is found to be proportional to the cube of its Gp for the gas is Gy PQ T v cont VY V temperature The ratio of 1 Y a 4I3 In the mi 3 arring on b 2 92 191 P2 c 5o 3 P1 1067 T 1024 NEET 2013 d 312

A block of mass m is kept on disc at rest Disc starts rotating with constant angular acceleration a Friction between block disc in sufficient to prevent slipping Which of the following is are correct 450 In inertial frame net force on the block is equal to friction force Normal on block increases with time Friction force will be towards centre Friction force on the block is not constant r

9 3 Two cylinders A and B fitted with pistons contain equal amounts of an ideal diatomic gas at 300 K Piston A is free to move and piston of B is fixed Same amount of heat is given to the gases in the two cylinders Temperature of the gas in cylinder A increases by 30 K Then increase in temperature of the gas in the cylinder B is y 14 for diatomic gas a 24 K b 36 K c 54 K e 9210 EAMCET 2013 d 42 K

hich vector sum is equal to the vector A in the diagram IF B A C D B C D E C C F P B C D KAI C

Current is flowing in a regular hexagon shaped loop of side length a Find expression for magnetic field at the centre Only one correct answer A B C pol 20 TO a 2 gl 70

A light of wavelength 414 nm falls on a metal surface having work function 1 eV Kinetic energy of fastest moving electron will be hC 1242 eV nm Only one correct answer A 3 eV B C 2 eV 1 eV

A Young s double slit experiment is performed using monochromatic light of wavelength X The intensity of light at a point on the screen where the path difference is is K units The intensity of light at a point where the path difference is is given by where n is an integer The value nk 12 of n is

For a sensitive potentiometer a the wire must be of small length b the external potential difference should be large c the wire must be of larger length d external potential difference should be small 1 Point Option a Option b Option c Option d

Force acting on a particle is F ayi Bxy j Find the work done in Joule by this force when particle is moved along the line 2x 3y from origin to the point 3 2 take all quantities in SI units and a 1 1

Problem 3 Consider a trough of a semicircular cross section and an inclined plane in it that leads from a point A to point B lying lower than A Prove that wherever point C is chosen on the arc AB an object will always get from A to B faster along the slopes ACB than along the original slope AB The change of direction at C does not involve a change in speed The effects of friction are negligible Problem The

al Electrostatic energy a Q 5n oa b Q 6n oa c 2Q 6ns a d Q 6n oa The volume charge density inside and outside a spherical charge distribution is as follows a p r r 0 b Calculate the total Electrostatic energy e 16m a c d e 6ea 20 6m a for 0 r a 6 a for r a

The state of polarization of light with the electric field vector E Eocos kz wot j Eo cos kz wt is b linearly polarized at 45 to x axis a linearly polarized along z direction c circularly polarized d ellliptically polarized with the major axis along x axis

A block of mass m is suspended from a spring Its frequency of oscillation is f The spring is cut into two identical halves and the same block is suspended from one of the two pieces of the spring such that it just touches the other spring below in its equilibrium position The frequency of small oscillations of the mass will be A E 56 elle 0 35 D Os 56

1 Calculate the mass of ascorbic acid Vitamin C CH O to be dissolved in 75 g of acetic acid to lower its melting point by 1 5 C K 3 9 K kg mol motic pressure in pascals exerted by a solution prepared

A particle of mass m as shown in figure Force F is being applied on trolley to move it on frictionless surface The angle 0 O O between string and vertical when particle is in equilibrium with respect to trolley is O DE tan tan tan wwwmmmmm m F 2mg F mg 2 F mg suspended by sless string a troll

1 T T 3 T T 2 T T 4 T 2T 2 The displacements of two particles executing SHM on the same line are given as y asin 2 0 and y bain 2 0 phase difference between them at f 1 sis 1 2 EN The

INEET 2013 26 A gas is taken through they cycle ABC A as shown What is the net work done by the gas 0 7 6 6x5 X10 X 4 3 2 2 1 0 a 2000 J p 105 Pa A 2 4 b 1000 J P T 6 B C 1x 0 8 c Zero 3 X 10 S S XI V 10 3 m Sylp d 20001

For finding the moment of inertia of a d isc with radius R we assume that the di sc is made up of many small rings of m ass dm radius x and width dx But as x tends to R the mass of the small rings s hould increase i e dm should increase The small ring which is farther from ce ntre should have a higher dm as compa red to those which are closer to centre But we assume that dm is constant for integration Why do we assume that all small rings should have the same mass dm Scientifically it is not possible

Let us plac shown in at M due identical conducting plate N parallel to it such that charge is induced on plate N a e If V is the potential at M due to induced negative charge on N and V is the potential Huced positive charge on N then The Q C Q V V V V Since V V as the induced negative charge lies closer to the plate M in comparison to induced positive C C Further if N is earthed from the outer side see figure then V V V the entire ositive charge flows to the earth harge C Q V Q V V C C M DO

26 The plot of velocity v versus displacement x of a particle executing simple harmonic motion is shown in figure The time period of oscillation of particle is 10 v m s 0 4 0 10 x cm 2 Is

A ball is dropped from the top of a tower After 2s another ball is thrown vertically downwards with speed of 40 ms After how much time and at what distance below the top of tower the balls meet a 30 m c 40 m b 37m d 45 m

4 The increase in internal energy of 1kg of water at 100 C when it is converted into steam at the same temperature and at 1 atmospheric pressure will be density of steam is 0 6 kg m latent heat of vaporisation of water 2 25 106 Jkg 3 9 X a 1 04 106 J c 4 16 106 J UK PMT 201 DQ ML b 2 08 x 106 J d 8 32 x 106J

Oscillations 121 0 A particle is executing SHM with time period T Starting from mean position time taken by it to 5 complete oscillations is 1 3 T 12 5T 12 2 4 7T 12

Question 26 M M 4 00 Switch S is closed at t 0 to begin charging of uncharged capacitor of capacitance C 15 F through a resistance C R 2002 The time after which potential difference across the capacitor is equal to that across the resistor is given by a ln 2 milli second Then write down the value of in OMR sheet 10 X N M 0 00 www R

Wave Optics Questions with Answer Keys math The speed of electrons in a scanning electron microscope is 1 107 ms 1 If the protons having the same speed are used instead of electrons then the resolving power of scanning proton microscope will be changed by a factor of outhongs mathongamathongs mathongo mathongo mathongo mathongs mathongo 1 1837 JEE Main 2021 2019 Chapter wise MathonGo mathongo mothongs

24 In single slit diffraction experiment first minima of red light A1 660 nm coincides with first maxima of other wavelength 2 What is the value of 1 440 nm 2 470 nm 3 550 nm 4 690 nm Find the ratio of least soparation betwe 5

0 At the first minimum adjacent to the central maximum of a single slit diffraction pattern the phase difference between the Huygen s wavelet from the edge of the slit and the wavelet from the midpoint of the slit is T a radian 4 T b radian 2 c radian I d radian

Question 22 20V M M 4 00 In the given circuit the value of R so that thermal power generated in R will be maximum in Q2 1092 www 30V 1002 492 www R N M 0 00 www 1202 40V www 3002 60V

A block of mass 0 2 kg is suspended from the ceiling by a light string A second block of mass 0 3 kg is suspended from first block through another string The ratio of tension in two strings is 2 3 3 2 O 1 2 O 5 3

A projectile of mass M is fired so that the horizontal range is 4 km At the highest point the projectile explodes in two parts of masses M 4 and 3M 4 respectively and the heavier part starts falling down vertically with zero initial speed The horizontal range distance from point of fringe of the lighter part is A 16 km 2013 C 10 km B 1 km D 2 km

The approximate compressibility and density of water is 10 kg m What fractional depth of an ocean is 2700m The of water is 45 4 x 10 Pa compression of water will be obtained at the bottom of the ocean Take g 10ms A 1 2 x 10 2 B C 1 4 x 10 C 0 8 x 10 2 10 x 10 2

2 Natural frequency of body 3 Difference of frequency of driving and natural frequency 4 Mean of driving force and natural frequency 18 Which of the following equation represents damped oscillation 1 3 dx dt dt kx dx dt 0 2 4 dx2 dt kx fo sin co d x dx dt k m x 0

and Three resistors having resistances r r2 r3 are connected as shown in the given circuit The iz ratio of currents in terms of resistances used 11 in the circuit is A i 1 3 r1 www r1 12 13 i2 r2 ww www 2 Deq 82B 03 0 83 82 r2 12 13 L901802 r1 r r2 rep B r t 3283 2 2

In Young s double slit experiment on the screen the 5th bright band due to one light of wavelength coincides with 6th bright band due to anothe light of wavelength A Then will be D d are same monochromatic monochromatic 1 1 B 5 6 C 6 5 D 4 5 A