Basic Physics Questions and Answers

1 2cos 8 d 1 3cos 8 13 A block of mass 2 kg is placed on the floor The coefficient of static friction is 0 4 A force F of 3N is applied on the block as shown in figure The force of friction between the block and the floor is Take g 10 m s c a 3N c 4N b d 8 N 6 N

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c 3 3 ms 3 ms d 3 m s 3 3 m s 6 A force F is related to the position of a particle by the relation F 10x N The work done by the force when the particle moves from x 2 m to x 4 m is a b 560 J d c 561 3 560 3 3J 560

cm d 70 cm c 60 cm 99 A policeman blows a whistle with a frequency of 500 Hz A car approaches him with a velocity of 15 m s The change in frequency as heard by the driver of the car as he passes the policeman is Given speed of sound in air is 300 m s a 25 Hz c 100 Hz b 50 Hz d 150 Hz 100 A band playing music at a frequency ui towards a wall at a speed

34 If a spring of force constant K is cut into two parts such that one part is thrice in length of the other part Th the force constant of each part are 4 2 3K 3K 1 4K 4K 2 4K 3 3 1K 4K 4 3

An open lift is coming down from the top of a building at a constant speed v 10 m s A boy standing on the lift throws a stone vertically upwards at a speed 30 m s w r t himself The time after which he will catch the stone is

121 A circuit is shown in the given figure Find out the charge on the condenser having capacity 5 F 2 F A 3 F 5 F 4 F 6 V B d 30 C

Red hot carbon will remove oxygen from the oxide XO and YO but not from ZO Y will remove oxygen from XO Use this evidence to deduce the order of activity of the three metals X Y and Z putting the most active first Question Type Single Correct Type 1 XYZ 2 ZYX

in the x The gravitational field due to a mass distribution is direction K is a constant Taking the gravitational potential to be zerc at infinity its value at the distance x is K 2x K 2x2

Total Marks 20 5 A gas under constant pressure of 4 5 x 105 Pa wher subjected to 800 kJ of heat changes the volume from 0 5 m to 2 0 m The change in internal energy of the gas is a 6 75 105 J 3 25x10 c b 5 25 x 1051 d 1 25 x 10 1

c 11 If a body placed at the origin is acted upon by a force F 1 3 2A then which of the following statements are correct 16 A forc relatic when a 1 Magnitude of F is 2 2 Magnitude of F is 2 2 3 F makes an angle of 45 with the Z axis Select the correct answer using the codes given 17 Two p 4 F makes an angle of 30 with the Z axis below a 1 and 3 c 1 and 4 b 2 and 3 d 2 and 4 1 Gum the ground with an c vector The ce a

i 3j 2k 18 Two thin discs each of mass M and radius r metre are attached to form a rigid body as shown in figure The rotational inertia of this body about an axis perpendicular to the plane of disc B and passing QO through its centre is a 2Mr 2 c 4Mr b 3Mr d 5Mr

The E M M values for Cr Mn Fe and Co are 0 41 1 57 0 77 and 1 97V respectively On joining which two electrodes we will get a cell with maximum voltage 1 Cr Mn 3 Mn Co 2 Mn Fe 4 Cr Co

A tank of height 5 m is full of water There is a hole of cross sectional area 1 cm in its bottom The initial volume of water that will come out from this hole per second is g 10 m s O 10 m s O10 4 m s O 10 m s O10 2 m s

b fo c for sound waves only d for both longitudinal and transverse waves 81 When two waves of almost equal frequencies u and u reach at a point simultaneously the time interval between successive maxima is a U U b v v 1 1 U U U U c d their organ pipe is doubled Ther second while w b a 2 89 There are 26 tu order of their beats with the What is the fre a 100 Hz b

There is a board on which IT is written It is situated on the opposite side of a river while IIT JEE aspirant swim the river such that he she always approach the IIT board ie he she always try to swim towards the board If speed of river and speed of aspirants w r t river are same and width of river is d 10 d A drift suffered by the aspirant will be 4 d B drift suffered by the aspirant will be 2 C If IIT board is taken away from the bank by distance d in perpendicular direction of river flow the 4d drift suffered will be 3 IIT board is taken away from the bank by distance d in perpendicular direction of river flow the 3d drift suffered will be

7 3 A block of silver of mass 4 kg hanging from a string is immersed in a liquid of relative density 0 72 If relative density of silver is 10 then tension in the string will be Take g 10 m s 37 12 N B 42 34 N D 21 15 N LA C 73 N

An electron of mass m initially at rest moves through a certain distance in a uniform electric field in time 1 A proton of mass m also initially at rest takes time t to move through an equal distance in this uniform electric field Neglecting the effect of gravity the ratio t t is nearly equal to A I C m m B m m 2 D 1836 An electron is projected as in figure with kinetic energy K at an angle 0 45 between two charged plates The magnitude of the electric field so that the electron just fails to strike the upper plate should be greater than

i A river of width 12 m flowing at 20 kph mixes with another river of width 8 m flowing at 16 kph and spreads in another stream of width 16 m Find the flow velocity of water after mixing assuming the depth of river are same 23 kph

wo small spheres are suspended from same point O on roof with strings of different lengths Both spheres move along horizontal circles as shown Then both spheres may move along circles in same horizontal plane STATEMENT 2 For both spheres in statement 1 to move incircular paths in samehorizontal plane their angular speeds must be same 1 Statement 1 is True Statement 2 is True Statement 2 is a correct explanation for Statement 1 2 Statement 1 is True Statement 2 is True Statement 2 is NOT a correct explanation for Statement 1 3 Statement 1 is True Statement 2 is False 4 Statement 1 is False Statement 2 is False

A synchronous generator is connected to infinite bus through a loss less line It is delivering initially 0 5 pu power to infinite bus The infinite bus voltage is 1 0 the maximum power transfer before fault is 1 0 pu The inertia constant is 6 MJ MVA the critical clearing angle is 75 then the critical clear time is in sec

Explain the source of stellar energy Explain the carbon nitrogen cycle and proton proton cycle occurring in stars If one microgram of 235 U92 is completely destroyed in an atom bomb How much energy will be released

The lengths of two cylindrical rods are measured as 5 62 0 01 cm and 2 4 34 0 02 cm What is maximum percentage error in of difference of lengths of two cylinders measurement O 1 6 O 2 34 O 1 95 O 3 16

8 A ball of mass m is released from A inside a smooth wedge of mass m as shown in fig What is the speed of the wedge when the ball reaches point B TITI 1 B 777 gR 2 3 52 N 45 1 R smooth 2 2gR 3 5gR 2 3 4 gR

2 R 150 N is the resultant of four concurrent forces of which only three are known Find the fourth force in magnitude and direction Refer Fig E 1 2 100N 60 60 120N 45 25 250N R 150N

acaA rope hangs from a rigid support A pulse is set by jiggling the bottom end We want to design a rope in which velocity v of pulse is independent of z the distance of the pulse from fixed end of the rope If the rope is very long the desired function for mass per unit length z in terms of o mass per unit length of the rope at the top z 0 g v and z is z 0 4 A H z Hoe 18 v 1z C z Ho log 3 z 2 Z B z e 8 v z D z Hoe

Which among the following statements is incorrect Accuracy of measurement shall depend on resolution of measuring instrumen As we reduce the errors measurement s accuracy increases O Smaller is the least count greater is the precision O More accurate measurement must have high precision

The uniform stick of m ss fir length L is pivoted at the centre In the equilibrium position shown in the figure the identical light springs have their natural length If the stick As turned through a small angle 0 it executes SHM The frequency of the motion is L2 M 1 2 V 6K m 3K 2m pivot 3K m L2 2 2 3 21 4 None of these

d seventh harmonic 60 Two open organs pipes of fundamental frequencies u and u are joined in series The fundamental frequency of the new pipe so obtained will be a U U UjU U U c V V U U d v v b om string

A circular coil of radius 0 157 m has 50 turns It is placed such that its axis is in magnetic meridian A dip needle is supported at the centre of the coil with its axis of rotation horizontal and in the plane of the coil The angle of dip becomes 30 when a current flows through the coil The angle of di becomes 60 on reversing the current Find the current in the coil assuming that the magnetic fiel due to the coil is smaller than the horizontal component of earth s magnetic field 4 x 107 V s A m and H 3 10 T

In a cage with plenty of plants three organisms P Q and R were kept together Out of these three two are herbivores while one is carnivore The changes in their population over time were plotted in the graph as shown here Which of the following conclusions can be made about their eating habits a Q is a carnivore that feeds on P d Population Time R Q is a herbivore that feeds on the available plants and is also not eaten by P R is a herbivore that does not feed on the available plants and is also not eaten by P Q is a carnivore that feeds on R

A sphere floats in water just submerged as shown in the diagram P 0 Answer If atmospheric pressure is neglected then A B C 20 D density of liquid p Your Attempt Correct answer Force exerted by liquid on lower half of sphere is 5pg R 3 Rate this que Force exerted by liquid on lower half of sphere and upper half of sphere is same in magnitude Ratio of magnitude of forces exerted by liquid on lower and upper half of sphere is Ratio of magnitude of forces exerted by liquid on lower and upper half of spere is 4

59 A is directed along north and B is directed south west If A B then which of the folo relations are correct a C must be equal to 7 B b C must be greater than A B c C must be greater than A B d C must be equal to A BI 60 What is the angle between A and the resultant of 7 69 and A B 67 Rotato

follows a track that turn to his right by an angle of 60 after every 100 m The displacement of the cyclist from the starting point to the fourth turn a 200 10 b 100 2 77

352 68 When a string fixed at its both ends vibrates in I loop 2 loops 3 loops and 4 loops the frequencies are in the ratio a 1 1 1 1 c 4 3 21 b 1 2 3 4 d 1 4 9 16 which 77 S

When constant torque is acting on a body then Question Type Single Correct Type 1 Body maintains its state or moves in straight line with same velocity 2 acquire linear acceleration 3 acquire angular acceleration o wit tant angu ala itu

The pitch of screw gauge is 1 mm and there are 100 divisions on circular scale While measuring diameter of a wire linear scale reads 1 mm and 39th division of circular scale coincides with reference line The zero error is 0 05 mm The correct diameter of wire is O 1 39 mm O 1 44 mm O 1 35 mm 01 034 mm

alve but we WORK velocity reversed 51 In case of a travelling wave the reflection at ang boundary will take place with a phase change of a radian b radian c radian d radian 6 52 A man standing between two parallel hill

68 White light is passed through a dilute solution of potassium permanganate The spectrum produced by the emergent KCET 2006 light is a Band emission spectrum b Line emission spectrum c Band absorption spectrum d Line absorption spectrum

Half life of a radioactive substance is 20 minutes Difference between point of time when it is 33 disintegrated and 67 disintegrated is approximately Question Type Single Correct Type 1 10 min 2 20 min 3 30 min

The osmotic pressure of CaCl2 solution is found to be 400 mmHg at 32 C Calculate the molar concentration of the solution Select one O 14 mol l O 10 mol m3 O 7 mmol l O 21 mol l

Define the distance a carbon dioxide molecule can diffuse in a cell for 0 1 s if the diffusion constant of carbon dioxide in water is 2x10 3 mm 2 s Select one or more 0 5 mm 20 m 100 m 0 02 mm

A person sitting in the ground floor of a building notices through the window of height 1 5 m a ball dropped from the roof of the building crosses the window in 0 1 s What is the velocity of the ball when it is at the topmost point of the window g 10 m s 15 5m s 14 5m s CORRECT ANSWER 14m s

Light with wavelength 442 nm passes through a double slit system that has a slit separation d 0 400 mm Determine how far away a screen must be placed in order that a dark fringe appear directly opposite both slits with just one bright fringe between them

A ball is dropped from 20m height and after striking the ground its 30 of energy is lost as heat then find the height attained by the ball after striking Question Type Single Correct Type 1 2 3 4 3m 6m 10m 14m

PASSAGE A laser emits light of wavelength 1 063 micrometer The output power is 20Watt Choose the correct options Marks 1 One example three level laser OPTIONS He Ne laser

laser system is capable of lasing at several infrared wavelengths where the most prominent wavelength is 3 1235 mm Given k 8 6x 10 5eV K or 1 38 X 10 power 23 J K The relative population of these states at 27 degree Cis OPTIONS 0 23 0 56 0 75

A particle of mass m is projected from origin O with speed u at an angle 0 with positive x axis Positive y axis is in vertical upward direction Find the angular momentum of particle at any time t about O before the particle strikes the ground again m ucose gt k 2 m ucose gt k 4 m ucose at k 1 415 3 m ucose gt k 11 2

r its In order to quadruple the resistance of a uniform wire a part of its length was uniformly stretched till the final length of the entire wire was 1 5 times the original length the part of the wire was fraction equal to 1 1 8 2 1 6 3 1 10 0 51

PASSAGE In 1924 the French physicist reasoned that nature was symmetrical and that the two basic physical entities matter and energy must have symmetrical character Read the following passage to answer the given questions based on it Choose the co options Marks 1 If electron is placed in 50 V potential difference what is gain in kinetic energy OPTIONS 8 10 18 J