Basic Physics Questions and Answers

For the loaded beam shown in the figure below A 25 KN 1m B 3m 40 kN C 5m Figure Q2 Loaded beam 20 kN Determine the reaction forces at the points of support of the beam shown in the figure Q above by applying the principle of equilibrium of moments Start your solution b drawing a free body diagram of the beam Develop the equations for shear force and bending moment for the spans AB BC and CI of the loaded beam shown above and for each equation developed determine the value of shear force and bending moment at the points A B C and D Draw the shear force and bending moment diagrams for the loaded beam shown above

The angle of prism is 60 In the position of minimum deviation which is 10 the value of angle of incidence i is 35 45 60 min se 30

Consider the following two statements A The primary rainbow is a result of three step process that is refraction reflection and refraction B The secondary rainbow is fainter than the primary rainbow The correct statement s is are O Only A Only B Both A and B Neither A nor B

19 An engineer works at a factory out of to wn A car is sent for him from the factory ev ery day and arrives at the railway station at t he same time as the train One day the engi neer arrived at the station one hour before h is usual time and without waiting for the car started walking towards factory On his way he met the car and reached his factory 10 m inutes before the usual time For how much time in minutes did the engineer walk befo re he met the car The car moves with the same speed everyday

53 Two wedges with angles of inclination 45 and each having a mass M lie on a smooth horizontal plane A ball of mass m drops freely from a height H It strikes one wedge and then the other and bounces vertically upwards Both the impacts are elastic Prove that the M m M m height to which it bounces is h H The wedges are supposed to be very near to each other

Water enters a pipe of radius 2 cm with a velocity of 2 m s The other end of the pipe has a radius of 1 cm and it is held vertically upwards The emerging water rises to a height of g 10 m s A 1 6 m P 32m

A boat is heading at angle 127 from the dire of flow The velocity of boat in water is 5 km R velocity of flow of water is 4 km h T displacement of boat along the flow of water width of the river is 1200 m 1 250 m 2 300 m 3 350 m

Blocks A and B of masses m and 2m respectively connected by an ideal spring of force constant k rest on a smooth horizontal surface see figure Block B is shifted distance I towards left and then released The velocity of centre of mass of the system of A and B after block A loses contact with the wall is

dl A block of mass m placed on a smooth horizontal surface is connected by two elastic strings ab and cd of equal length Young s modulii Y 2Y areas of cross section A A 2 and a spring spring of force constant C Both the strings and the spring are in unstretched condition Find the time period of small oscillation of the block along the horizontal surface

onsider a light wire of Young s modulus Y cross sectional area A and leng L If a constant force F is applied at the end of the wire as shown then A Elongation in wire will be FOL AY B Work done by force F will be D Flengs Y A L IF F L 0 AY F L 1 0 C Loss of mechanical energy is 2 AY 2F L

20 A chain of mass 2 kg is placed on a smooth table th of its length hanging over the edge NEET with 4 If the length of chain is 4 m then the work done in pulling the hanging portion of the chain back to the surface of the table is NCERT Pg 118 1 5 J 3 2 J 2 2 5 J 4 4 J

A 100 mm diameter pipe is used to transport crude oil If the pressure drop over an 8 m length is 500 Pa determine the average velocity of the oil flow Do you expect the flow to be laminar or turbulent Hint Check the Reynolds number Take the viscosity of crude oil to be 30 2x10 3 N s m2

Consider the following two statements A Light of shorter wavelengths is scattered more than light of longer wavelengths B Our eyes are more sensitive to blue than violet The correct statement s is are Only A Only B Both A and B Neither A nor B

A string of negligible mass natural length L has Young s modulus Y The strin hangs from roof with masses m and m as shown in the figure If mass m removed swiftly consequently the mass m is just able to bounce back upt point O Find the ratio m m string will not obstruct the motion of mass m and system is initially in equilibrium 2 L m

The figure shows a cube of mass mand edge length a mounted on an axle through its centre A spring of force constant k connects the cubes upper corner to a rigid wall Initially the spring is in natural length If the cube is given a small angular displacement and released its angular frequency is oxal 1 el 3 3k m k oooooo za 2 1 a a 2k m N 00 1 k acost

A plank of mass M rests on a smooth horizontal plane A sphere of mass m and radius r is paced on the rough upper surface of the plank and the plank is suddenly given a velocity v in the direction of its length Find the time after which the sphere beings pure rolling if the coefficient of friction between the plank and the sphere is u and the plank is sufficiently long

Coghlan Paragraph for Questions 11 and 12 Electric field in a region is given by following equation E To i j and an imaginary cube is made as shown in the diagram X 0 2 0 K F Fo r Fol 11 Find total flux through this cube due to the given electric field A 47K B 6 K C 16K 12 Find total charge encloses in this imaginary shown cube A 4K E B SK C 6K where r xi yj and D SK D 2K

If the focal length of objective and eye lens are 1 2 cm and 3 cm respectively and the object is put 1 25 cm away from the objective lens and the final image is formed at infinity The magnifying power of the microscope is 150 O 200 250 100

A telescope has objective of focal length equal to 150 cm and eyepiece of focal length 2 cm The magnifying power of this telescope for normal adjustment will be 100 O 75 25

Three small balls each of mass 10 gm are suspended separately from common point by silk threads each one meter long The balls are identically charged and hang at the corners of an equilateral triangle of side 0 1 metre Find the charge on each ball

A planet is revolving around the sun S in an elliptical path with semi major and semi minor axes as a and b respectively If time for one complete revolution is T then time taken by planet to move from point A to B as shown in figure will be T N find the value of N a B S a 1 A ET

An astronomical telescope has an angular magnification of magnitude 5 for distant objects The separation between the objective and eye piece is 36 cm and the final image is formed at infinity Determine the focal length of objective 6 cm 20 cm 30 cm

D A potential difference of V is applied at the ends of a copper wire of length 1 and diameter D On doubling only D drift speed a becomes double c does not change d becomes half b becomes one fourth

The refracting angle of a prism for a monochromatic light is 60 and refractive index is 2 For minimum deviation the angle of incidence will be 60 45 30

Three identical bulbs are connected to a battery as shown in figure Each bulb is operate at normal brightness and the ammeter registers a steady current If filament of one of the bulb breaks then what happens to the ammeter reading and the brightness of the remaining bulbs HHH

10 Single answer type A body is projected upwards at an angle 30 to the horizontal and the range is R Another body is projected upwards at an angle 60 with the horizontal and the range is R If both the bodies have the same initial velocity then A Review Later R 2R

A certain metal must absorb radiation with a wavelength no larger than 275 nm in order to eject an electron from its surface via the photoelectric effect Calculate the work function of this metal in units of kJ mol

Q7 The Equivalence of Inertial and Gravitational Mass a Show that if a distinction between the inertial mass m and the gravitational mass mg of the bob is maintained then the period of a simple pendulum length L is given by m L mgg b Now describe an experiment you could do or Newton or Galileo might have done to test the equivalence of inertial and gravitational mass T 2

aceship flies past a spacestation at high speed On board is an atomic clos lled A n the point of view of an observer on the spacestation clock A runs slow one second on clock A takes 2 seconds to pass as measured against an tical clock B which is on the spacestation in the point of view of a traveller on the spaceship how long does a secon kB take to pass as measured by clock A

A spring balance is attached to the ceiling of a lift A man hangs his bag on the spring and the spring reads 49 N when the lift is stationary g 9 8 m s A If the lift moves downward with an acceleration of 5 m s the reading of the spring balance will be 24 N B If the lift moves upward with an acceleration of 5 m s the reading of the spring balance will be 24 N If the lift moves downward with a constant velocity of 5 m s the reading of the spring balance will be 49 N D If the lift moves upward with an acceleration of 5 m s the reading of the spring balance will be 74 N

TM 4 12qB 3 6qB A ring of radius r rotates with frequency v abou own axis If linear charge density is the magnetic field at centre is 1 v 2 v 1 3 Mo 4 Zero A current carrying conductor is placed as shown A straight two parts circular centre

5 a How do you account for the presence of unmodified component of X rays in the study of Compton effect b Explain how the wave theory fails to explain Compton effect c What is the maximum KE of the recoil electron in Compton effect Is it possible for a photon to transfer is entire energy to the electron d Can you see Compton effect with visible lights Give reasons to your answer

Three bulbs consume same energy when operated at 200 V 300 V and 400 V respectively When these bulbs are connected in series across a dc source of 1000 V then One More Correct Answer s B C D Ratio of potential difference across them is 8 3 4 Ratio of potential difference across them is 4 9 16 Ratio of power produced in them is 4 9 16 Ratio of power produced in them is 2 3 4

A block X of mass m strikes another block Y of mass 2m Bo the blocks collide and at point of collision the block X exerts th force of 10 N to block Y What will be the size and direction of th force exerted by block Y a b c d 10 N in the same direction of force of block 20 N in the same direction of force of block X Haftentla 10 N opposite to the direction of force of block X 20 N opposite to the direction of force of block X

f force X y is dimensionally correct the dimensions of xy are Area M L4T 4 O ML T 4 Read More O ML T 2

Two convex lenses are placed in contact as shown in figure a The combinatio has focal length 25 cm If a liquid of refractive index same as glass is introduce between them as shown in figure b The power of the system 0000 a b

b A horizontal force of 5 kN is acting on the wedge as shown in Fig 3 b the coefficient of friction at all rubbing surfaces is 0 25 Find the load W which can be held in position The weight of block B may be neglected 60 W B Fig 3 b 5 kN

Maps What are a the x coordinate and b the y coordinate of the center of mass Figure 9 37 Pr for the uniform plate shown in Fig 9 38 if L 5 0 cm I 21 Figure 9 38 Problem 5 I

laboratory frame a massless particle with momentum 80 GeV c collide nother massless particle with momentum 40 GeV c and the two partic late To the nearest integer in units of GeV c what is the mass of the est particle they could hypothetically produce

25 A uniform measuring chain of length is tightly stretched over a river the middle point just touching the surface of the water while each of the extremities has an elevation k above the surface Show that the difference between the length of the measuring chain and the breadth of the river is approximately 8k 31

current is 100 connected to pere is ti has The 1 2 m qB M 0 30 X X X X X 2 CO B TUM 3qB TUM NEET 3 mv 2qd 2mv qd 4 SECTION Previous Years Two toroids 1 and 2 and 100 respectively 20 cm respectively the ratio of the m loops is 1 1 2

8 A motor cycle starts from rest and accelerates along a straight path at 2 m s At the starting point of the motor cycle there is a stationary electric siren How far has the motor cycle gone when the driver hears the frequency of the siren at 94 of its value when the motor cycle was at rest Speed of sound is 330 m s a 49 m b 98 m c 147 m d 196 m AIEEE 2009

Q 11 A rectangular block is placed on a rough horizontal surface in two different ways as shown then a F b a friction will be more in case a b friction will be more in case b 100 c friction will be equal in both the cases d friction depends on the relations among its dimensions

A particle is created in a high energy collision in the Large Hadron Collider and decays after 10 s as measured in its rest frame If the particle was travelling at 60 the speed of light in the laboratory frame how long did it live in us before decaying in this frame

CERT Based The height of mercury in the barometer tube is 70 cm due to entrapped air in it as shown in figure Now from this position tube is pulled up slightly then length of the mercury column in the tube will NCERT Pg 254 not perfect vacuum L 70 cm 1 Remain 70 cm 2 Slightly more than 70 cm

13 A ball is projected in a direction inclined to the vertical and bounces on a smooth horizontal plane The range of one rebound is R If the coefficient of restitution is e then range of the next rebound is 1 R eR 2 R e R 3 R 4 R R e

front of the lens ght travels from air to glass creates 25 angle of refraction What is the angle incidence of glass has a refractive index of 1 52 A 16 B 30 C 40 D 45 6 th following long and mairros con scatter light rays

i Obtain an expression for rotational energy levels of a diatomic molecule State the election rule and draw the energy levels of L 0 L 1 L 2 and L 3 ii Calculate the frequency of the spectral line corresponding to an energy change of 005 eV

5 A block of mass m starts from rest and slides down a frictionless semi circular track from a height h as shown When it reaches the lowest point of the track it collides with a stationary piece of putty also having mass m If the block and the zt putty stick together and continue to slide the maximum height that the block putty system could reach is 1 h 4 2 h 2 3 h 4 independent of h

5 A solid cylinder of mass 2 kg and radius 4 cm is rotating about its axis at the rate of 3 rpm The torque required to stop it after 27 revolutions is a 2 106 Nm c 2 10 Nm b 2 106 Nm d 12 10 Nm NEET