Basic Physics Questions and Answers

Calculate the wavelength of sodium light In a biprism experiment with sodium light bands of width 0 0195 cm are observed at 100 cm from slit given On introducing a convex lens 30 cm away from the slit between biprism and screen two images of the slit are seen 0 7 cm apart at 100 cm distance from th lit B 4450 5850 Correct Answer 3650 6750

A charged particle moves inside a smooth pipe which is bent as shown in figure If R mv 9B exerted by the pipe on charged particle at P is q 1 Towards center 22 7am R P then force XB 2 Away from center 4 Toncontial

Five point charge each having magnitude q are the corner of hexagon as shown in fig Net electric field the centre O is E To get net electric field at O be 6E charge placed on the remaining sixth corner should be q O q b 6 a

A point object is moving on the principal axis of a concave mirror of focal length 24 cm towards the mirror When it is at a distance of 60 cm from the mirror its velocity is 9cm sec What is the velocity of the image at that instant 1 5cm sec towards the mirror 2 4cm sec towards the mirror 3 4cm sec away from the mirror 4 9cm sec away from the mirror

ALLEN 10 A bob is hanging inside a car through a massless string as shown in figure The car is moving with constant acceleration a horizontally The bob makes an angle 0 with the vertical at equilibrium Then which of the following statement is correct 1 0 is independent of a 2 With increase of a 0 will decrease 10

The vector product of given two vectors A 31 4j 5k and B 21 j k is 1 9i 13 11k 3 91 7 11k in NCERT Pg 152 2 97 13j 11k 4 9 7 11k

A particle of charge q and mass m is projected perpendicular to a magnetic field B and it is observed to rotate w r t an axis whose direction is given by the vector 21 23 3k with an angular speed of 17 rad s in a circular path If the charge to mass ratio q m of the particle is 3 C kg find the magnetic field B

3 A block has an initial kinetic energy of 128J It slides up from point A at the bottom of the inclined plane with uniform deacceleration When it passes point B its Kinetic energy is reduced by 80J and its mechanical energy is reduced by 35J Calculate the work done against friction when the block moves from A to the highest point C on the inclined plane A 42J B 48J C 56J D 72J

given ligure the path of light bec omes visible in beaker b but not in bea ker a This is due to a dispersion takes place in colloidal so lution only b refraction takes place in true solutio n only c beaker a is true solution and beaker b is colloidal solution d beaker b is true solution and beaker a is colloidal solution Torch 09 a b Path of light becomes visible Fig 2 3 a Solution of copper sulphate does not

en potential energy U spring versus its position x is best sh by graph equilibrium x 0 1 2 3 M x 0 U 0 U I 0 NCERT Pg X X Xm X X

Find Temperature T the location where potential is 200V and isothermal equations between two coaxial cylinders of radii 1 and 1 having Temperature T and T respectively where 1 2 cm 1 6cm T 300 V and T 100V

Resistances P Q S and R are arranged in clockwise cyclic order to form a balanced Wheatstone s bridge The ratio of electric power consumed in the branches P Q and R S is A 1 1 B R P C R2 P2 C C

Two balls of masses m and 2m moving along a straight line approach each other with a velocity of 10 m s collide inelastically If the magnitude of their relative velocity just after collision is 6 m s then the coefficient of restitution is A zero B 0 4 C 0 6 D 1 0

A ball is projected vertically upwards from th ground It takes 4 s to reach a point P still movin upwards If it takes 10 s further to reach to ground then height of point P is 1 180 m 3 400 m 2200 m 4 480 m

lehs with objective of focal length 0 5 cm and eye piece of focal length 5 and the lenses are separated by 7 cm What is the magnification of microscope when final image is formed at infinity 12 14 5 15 18

In the given figure the path of light become s visible in beaker b but not in beaker a Th is is due to a dispersion takes place in colloidal solutio n only b refraction takes place in true solution onl y c beaker a is true solution and beaker b is colloidal solution d beaker b is true solution and beaker a is colloidal solution Torch 10 a b Path of light becomes visible Fig 2 3 a Solution of copper sulphate does not show Tyndall offart h mixture of water

kept If the tension of one wire is increased by AT then the N beats s occur when both wires oscillate simultaneously The correct statement is Options 1 2 3 4 2 AT N 4 4 8 1 T AT T AT T AT T fo f N fo N fo fo N fo 2 1 2 2 1

HEFONDE Two thin rigid rods AB mass m length and CD mass 2m length 2 are connected to make a T as shown in figure The assembly is kept vertical on a frictionless horizontal surface and is restrained to fall sidewise What is the least value of F to be applied horizontally at B such that B is able to leave contact with the surface C O 3mE 2 mg 3 3 2 mg 21 2m D m B A F

A ball is dropped from rest at time t 0 from certain height A second ball is dropped from same height at time t 1 s At what time t the distance between two balls becomes 10 m Options 1 2 3 1 25 s 1 5 s 1 75 s 2 s

A monochromatic light of wavelength 623 8 nm is incident at an angle of 40 from the vertical into the oil and it refracted to 22 from the vertical Find the speed and wavelength of this light in the oil a 1 65 108 m s 410 nm b 1 75 108 m s 363 nm c 1 97 108 m s 210 nm d 1 97x10 m s 210 nm

5 1 During measurement of kinetic energy T the percentage error in measurement of mass of particle and momentum of particle are 2 and 3 respectively The percentage Tror in measurement of kinetic energy is n Find the alue of n 10

A Carnot engine is working between 127 C and 27 C The increase in efficiency will be maximum when the temperature of a the source is increased by 50 C the sink is decreased by 50 C b e d source is increased by 25 C and that of sink is decreased by 25 C both source and sink are decreased by 25 C each

A man goes 10m towards North then 20m towards east then displacement is A 22 5m B 25m C 25 5m D 30m A body moves over one fourth of a circular track in a circle of radius r The magnitude of distance travelled and displacement will be respectively D r r TLT A B TIT r r C T 2

The true value of a particular mass is 8 5 g The four instruments A B C D used to measure mass gives the reading as 8 2 g 8 48 g 8 186 g 8 g respectively Which of these instruments more accurate NCERT Pg 2 2 B

51 A compound microscope has a magnifying power of 100 when the image is formed at infinity The objective has a focal length of 0 5 cm and the tube length is 6 5 cm The focal length of eye piece is A 4 cm B 2 cm C 6 cm D 5 2 cm

AgNO3 does not give precipitate with chloroform because A CHCl3 is insoluble in water C CHCl3 is an organic compound 1 B CHC13 does not ionize in water D AgNO3 is insoluble in CHC13

6 Speed of the a particle emitted from stationary 238 U nucleus is 2 34 x 105 m s 98 Speed of the daughter nucleus is 1 4 x 103 m s 2 103 m s 3 2 34 x 105 m s 4 2 34 x 10 m s

What is the minimum angular speed with which a 200 turn flat coil of cross sectional area of 300 cm can be rotated in a uniform 30 mT magnetic field if the maximum value of the induced emf is to equal 12 0 V O 5 3 rad s O 50 rad s 67 rad s O 0 19 rad s

Problem 2 At 1 atm 1 013 x 10 Pa and 23 C how many moles of air are in 25mL Also find the number of molecules 13 points Problem 3 At the surface of water where the pressure is latm a diving bell is filled with air When the diving bell is lowered only 30 of its volume is air What is the pressure inside the diving bell in atm after being

A star of radius Rs with surface temperature T radiates light according to the blackbody spectrum into the cold background of space T 0 K At a distance d away from the star a planet with radius Rp d Rp absorbs this radiation Assume planet to be a black body Planet s surface comes to a uniform temperature Tp Answer A B C Your Attempt Tp Ts Correct answer R 2d T T Re Tp Ts S dE dt d The energy time radiated back to star by planet in steady state is TR R 4d Rate this question OT The energy time radiated back to star by planet in steady state is 2 ml

A crane is used to lift 1000 kg 100 m deep The time taken by the crane is 1 hour The efficiency of the crane is 80 If g 10 ms 2 then the power of the crane is a 104 W 9 b 105 W c 104 W 36x8 d 105 36x8 W

For plane electromagnetic waves propagating in the z direction which one of the following combination gives the correct possible direction for E and field respectively A i 2j and 2i j B 21 3j and 31 23 skipped c 21 3j and i 2j D 31 4j and 4i 3j 2

8 A sphere of aluminium of 0 5 kg is placed for sufficient time in a vessel containing boiling water So that the sphere is at 100 C It is then immediately transferred to 0 20 kg copper calorimeter containing 0 30 kg water at 20 C The temperature of water rises and attains a steady state at 25 C The specific heat capacity of aluminium will be Scu 386 J kg k and Sw 4180 J kg k 1 887 5 J Kg 1 K 1 3 1965 K 1 K 1 2 177 49 J Kg K 1 4 2118 J Ka 1 K 1

A particle is moving eastward with a speed of 5 m s In 10 s the velocity changes to 5 m s northwards The average acceleration in this time is 1 zero 1 2 m s towards north west

35 Consider a Lagrangian of the form L m x w x er where the particle of mass m moves in one direction Assume all constants are posi tive a Find the equations of motion b Interpret the equations by giving a physical interpretation of the forces acting on the particle c Find the canonical momentum and construct the Hamiltonian Is this Hamiltonian a constant of the motion d If initially x 0 0 and dx dt 0 what is x t ast approaches large values

C 2 In following diagram boxes may contain resistor or battery or any other element 28 1A i 10 V 10 A 1A I no box 10 V 12 B then determine in each case a E m f of battery b Battery is acting as a source or load c Potential difference across each battery d Power input to the battery or output by the battery e The rate at which heat is generated inside the battery 1 The rate at which the chemical energy of the cell is consumed or increased g Potential difference across box

The velocity of end A of rigid rod placed between two smooth vertical walls is u along vertical direction Find out the velocity of end B of that rod rod always remains in contact with the vertical wall and also find the velocity of centre of rod Also find equation of path of centre of rod A u

From the following the quantity constructed from the basic constants of nature that has the dimensions as well as correct order of magnitude vis vis typical atomic size is B 4 h A C e 4 m me 2 4 b 2 r 22 4 KEO MC D me 4 m e 2013 E mc R9 92 r

A particle of mass m is located in a one dimensional potential field where the potential energy of the particle depends on the coordinates x as v x Vo 1 cosax Find the period of small oscillations that the particle performs about the equilibrium position

In the circuit shown in the figure current through the resistance R3 is A R 10 92 8 A R 592 Zero 2 A 3 A 3 R 1002 B R 102

resonating structure NCERT XI 354 1 CH3 C 0 CH3 C O O 2 CH CH C H CH CH C H 3 CH3 CO CH3 CH3 C C O CH3 4 CH CH GL CH CH Cit

at t 0 ring the 3 48 A capacitor of capacitance 6 F and initial charge 160 C is connected with a switch S and resistors as shown in figure 3 346 If switch is closed at t 0 then the current through resistor of 402 at t 16 s is A C 10 e A 10 A 3e 8523 S C od sta Figure 3 346 xol B of 20 A 3e D zero 452 aqo 2 dosiwe oris awolt tett ogsdolo

cm from A point object O is placed at distance of concave morror between a concave and a plane mirror separated by 25cm Considering 1st reflection from concave mirror position of image after 3rd reflection will be Radius of curvature of concave mirror is 20cm P O 15cm 10cm 1 At 20cm from P 2 At 30cm from P 4 At 40cm from P 1

The value of current i in the electrical network as shown in the figure is 2 A 1 A 10 A 2 A 3 A 4 A 8 A 11 A 3 A 1 A i

1 An electric motor is used to fill an overhead tank of capacity 10m kept at a height of 20 m above the ground If the pump takes 6 minutes to fill the tank by consuming 20 kW power the efficiency of the pump should be a 10m s

Chaitanya IIT Academy 27 12 15 Sr IPLCO JEE ADV 2014 P1 RPTA 16 Q Paper Consider a two particle system having the properties as mentioned in the diagram The system is rotating about the common center of mass Assume Bohr s quantization principle to be valid for this system If the radius Ro x find the corresponding to the first energy level of the electrons orbit is value of x Ro is the radius of first orbit of H atom 2M 3e M e

3 Calculate the increase in internal energy of 1 kg of water at 100 C when it is converted into steam at the same temperature and at 1 atm 100 kPa The density of water 3 and 0 6 kg m 3 and steam are 1000 kg m respectively The of vaporization of water heat 1 latent 2 25 x 10 J kg

Calculate the value of the total current passing through the resistors when the resistors 15 and 20 are connected in the circuit The potential difference applied to the combination of the two resistors is 35 V A 4 08 A B 2 08 A C 1 00 A D 2 22 A

Q6 A non planar loop of conducting wire carrying a current I is placed as shown in the figure Each of the straight sections of the loop is of length 2a The magnetic field due to this loop at the point P a 0 a points in the direction 2001 2 C 21 A B k Il D 1 2

The charge stored on the capacitor in steady state condition in the following circuit is 2 uF www 502 tr 10 V 5 C O 10 C 20 C 502