Basic Physics Questions and Answers

An electron accelerated through a potential difference V passes through a uniform transverse magnetic field experience a force F If the accelerating potential increase to 4 V the electron in the same magnetic field will experience a force OF 2F 2F

A light uniform rod of 3 m length is pivoted at one of its ends and a small sphere of mass 0 5 kg is attached at the other end as shown in the Figure The rod with the sphere is at rest in the horizontal plane with two attached springs S and S each of spring constant 1000 Nm The time period of small oscillation of the sphere about the pivot O is in ms O O O O 30m 60m 40m 20m 1m 8 Im 0 5 kg

A vertical cylinder contains an ideal gas enclosed at a pressure of 2 atmospher e by means of a freely moving piston c ontaining weights The cylinder is place d on a lift which rises with an accelerati on of g 3 The fractional change in volu me of the gas is Does the gas gets co mpressed

Is it necessary for a transmitting antenna to be at the same height as that of the receiving antenna for line of sight communication A TV transmitting antenna is 81 m tall How much service area can it cover if the receiving antenna is at the ground level

62 A ball is dropped vertically from a height d above the ground It hits the ground and bounces up vertically to a height d 2 Neglecting subsequent motion and air resistance its velocity v varies with the height h above the ground can be plotted as 215

2m 16 Four particles of mass m m 4m m3 m and m4 are placed at four corners of a square What should be the value of m4 so that the center of mass of all the four particles are exactly at the center of the square a 2m b 8m c 6m d None of these m t M3 M

a Lord Canning b Lord Mountbatten c dtipon d Lord Wellesley Question 2 Medieval period was a the old period of history b the period associated with the growth of all the forces of modernity c none of the above Question 3 The British thought surveys were important for a writing history b effective judgement c effective administration d none of these Question 4 The British preserve official documents because a the preserved documents reveal the progress made by country in the past b one can study the notes and reports which were prepared in the past c their copies may be made and used in modern times d all of the above Question 5 Which one of the sources do historians use in writing about the last 250 years of Indian history a Official records of the French administration b Official records of the British administration c Official records of the Church administration d None of the above Question 6 Which of the following is NOT the period of division of Indian History by James Mill a Hindu b Muslim c Christians d Sikhs Question 7 Which is NOT the source of describing history a Diaries of people b Conversation between two people c Accounts of pilgrims and travellers d Autobiographies of important personalities Question 8 The National Archives of India came up in the a 1910s b 1920s c 1930s d 1940s Question 9 Which of the following was NOT the Presidency a Bengal b Madras c Bombay d Kalikata Question 10 Tipu Sultan stopped export through his kingdom in

Your car is stuck in a mudhole You are alone but you have a long strong rope Having studied physics you tie the rope tautly to a telephone pole and pull on it sideways as shown in figure Find the force exerted by the rope on the car in N when the angle 0 is 3 and you are pulling with a force of 314 N but the car does not move F Telephone pole

The mass in the figure can slide on a frictionless surface When the mass is pulled out spring 1 is stretched a distance x and spring 2 is stretched a distance x The spring constants are k and k respectively Magnitude of spring force on the mass 1 2 1 2 is k k 00000000000 000000000000 1 k x 2 k x k x 3 k x k x 4 All of th

Une end of cylindrical glass 1 5 is given a snape of concave refracting surface of radius of curvature 10 cm as shown in the figure An air bubble is situated in glass rod at a point on its axis such that it appears to be at 10 cm from surface inside glass The actual location of bubble inside glass from surface is 1 5 Bubble 12 cm 20 cm 30 cm 36 cm R 10 cm

Water is flowing through the uniform horizontal tube of cross sectional area A with constant speed vas shown in figure The magnitude of force exerted on bend corner of the tube will be Water density is p PA 2 60 2 pav 2 O 3pAv 2 3 PAV

A particle is dropped from rest from a height The time taken by it to fall through successive vertical distance 1 meter each will then be 2 1 all equal being equal to second 2 in the ratio of square roots of integers 1 2 3 3 in the ratio of the difference in the square roots of integers T 016 2 3 211 4 3 4 in the ratio 1 1 2 3 4

Light with an energy flux of 18 W cm falls on a non reflecting surface at normal incidence If surface has area of 2 m what is force exerted on surface O 12x 10 4 N O 12 x 10 5 N 2 4 10 5 N 24 10 4 N

In a common emitter configuration transistor current amplification factor 45 change in voltage across 5 k resistor connected in collector circuit is 5 V The change i base current is 0 01 MA 0 022 MA 0 37 mA

The potentiometer wire AB shown is 40 cm long of resistance 5002 m free end of an ideal voltmeter a is touching the potentiometer wire at the middle initially What should be the velocity of the jockey as a function of time so that reading in voltmeter is varying with time as 2sin mtr 10 2V lov P DV uv 1002 Tonn ito 10 4 0 10 20serat de ov 2011 Cost V SB R

Example 5 In a two slit experiment with monochromatic ight fringes are obtained on a screen placed at some listance from the plane of slits If the screen is moved by cm towards the slits the change in fringe width is 30 m If he distance between the slits is 1 mm calculate wavelength of the light used

A particle is moving along a circular path of radius R in such a way that at any instant magnitude of radial acceleration is half of tangential acceleration If at t 0 velocity of the particle is vo Then find the speed of the particle after one complete revolution 1 v voe 2 V Voe4 v v e 3 4 v Voe

The transition from the state n 4 to n 3 in a hydrogen like atom results in ultraviolet radiation Infrared radiation will be obtained in the transition from a 2 1 c 4 2 AIEEE 2009 CBSE PMT Mains 2012 b 3 2 d 5 4

Q No 52 Which of the following statement is true about brittle fracture High temperature and low strain rates favour brittle fracture Many metals with hexagonal close packed H C P crystal structure commonly show brittle fracture Brittle fracture is always preceded by noise Cup and cone formation is characteristic for brittle materials A B C D

Two ball A and B of same mass are thrown from the top of the building A thrown upward with velocity and B thrown down with velocity v then 1 velocity A is more than B at the ground 2 velocity of B is more than A at the ground 3 both A and B strike the ground with same velocity 4 none of these

Q No 49 Which of the following statements are true for annealing of steels ABCD A B C D Knowledge Sections Steels are heated to 500 to 700 C Cooling is done slowly and steadily Internal stresses are relieved all of these

A square loop of side a has resistance R and lies at distance a from an infinite straight wire carrying lo Find the charge flown through the loop when the loop has turned through an angle of 120 about an axis AB as shown 1 3 10 Hola 3 1 2 R a Hola In 1 In2 B A 2 4 C Hola 3 In 2 R 2 Hola In 2

Cos 0 43 A vessel containing water is given a constant a towards the right along a straight acceleration horizontal path Which of the following diagram represents the surface of the liquid A 1 A B 2 B cos0 C 3 C D 4 D

Q No 58 The stiffness is the ability of a material to resist A B C yielding D deformation under stress fracture due to high impact loads externally applied forces with breakdown or Knowledge Sections none of the above 10

Q No 56 The strength is the ability of a material to resist ABCD A C D deformation under stress externally applied forces with breakdown or yielding fracture due to high impact loads none of these

Q 13 O 1 A body moves in a straight line for some time and then returns to the starting point If the total time taken by the body to complete this path is 20 s and the total distance travelled is 40 m then which of the statements is incorrect regarding the motion of the body O 00 05 The displacement of the body is 20 m The displacement of the body is zero The average speed of the body is 2 0 m s The average velocity of the body is zero 000

Q No 55 When elements like nickel chromium copper and molybdenum are added to the molten cast iron it produces ABCD A B C D white cast iron nodular cast iron malleable cast iron alloy cast iron

Q 19 O A boat travels 50 km east then 120 km north and finally it comes back to the starting point through the shortest distance The total time of journey is 3 h What is the average velocity in km h over the entire trip O 33 33 17 86 7 00 01 Zorn O

A simple pendulum is being used to determine the value of gravitational acceleration g at a certain place Th length of the pendulum is 25 0 cm and a stop watch with Is resolution measures the time taken for 40 oscillations to be 50 s The accuracy in g is 1 3 40 2 5 40

Pre Medical Physics If the rotational velocity of a dynamo armature is doubled then induced e m fwill become 1 half 2 two times 3 four times 4 unchanged

A block of mass m is at rest under the action of force F against a wall as shown in the figure Which of the following statements is incorrect a f mg b F N where f is frictional force where N is normal force c F will not produce torque d N will not produce torque E a

A monkey of 40 kg climbs on a massless rope of breaking strength 600 N The rope will break if the monkey g 10ms 2 1 climbs up with a uniform speed of 6m s 2 climbs up with an acceleration of 5 m s 3 climbs down with an acceleration of 4 m s 4 climbs down with unif

A network is given as shown Switch was at position 1 for long time At t 0 it is shifted to position 2 then Neglect mutual induction between coil 202 10V 4H 1 wamo IH 202 Current just after switching is 20 Amp Current just after switching is 4 Amp

6 Six forces lying in a plane and forming angles of 60 relative to one another are applied on a sphere of mass 6kg These forces are acting radially outward and consecutively 1N 2N 3N 4N 5N and 6N The acceleration of the sphere is 2 0 5 m s 4 2 m s 2 1 0m s 3 1m s

A syringe is filled with water up to volume 20 cm The area of cross section of the cylinder is 5 cm The syringe is held vertically and its 90gm piston is pushed upward by external agent with constant speed of 4 mm s A water beam coming out of the small nozzle hole area 1 mm Neglecting friction and viscous nature of water find the work done by the agent in 10 2 J in fully emptying the syringe take g 10 m s Assume ideal liquid

Two liquids of densities p an p p 2p are filled up behind a square wall of side 10 m as shown in figure Each liquid has a height of 5 m The ratio of the forces due to these liquids exerted on upper part MN to that at the lower part NO is Assume that the liquids are not mixing M N 0 5m 5m

Q No 45 The hardness of steel depends upon the ABCD A B C D amount of cementite it contains amount of carbon it contains contents of alloying elements method of manufacture of steel Knowledge Sections

Q No 40 Free carbon in iron makes the metal A B C D soft and gives a coarse grained crystalline structure soft and gives a fine grained crystalline structure hard and gives a coarse grained crystalline structure hard and gives a fine grained crystalline structure

Q No 37 In full annealing the hypo eutectoid steel is heated from 30 C to 50 C above the upper critical temperature and then cooled A ABCD B C D in still air slowly in the furnace suddenly in a suitable cooling medium any one of these

contained An ideal gas of molar mass M is in a very tall vertical cylindrical vessel in the uniform gravitational field in which the free fall acceleration equals g Assuming the gas temperature to be the same and equal to T find the height at which the centre of gravity of the gas is located

Q No 38 The lower critical temperature ABCD A B C D decreases as the carbon content in steel increases increases as the carbon content in steel increases is same for all steels depends upon the rate of heating

Two pulses are created on the rope at points A and B respectively as shown in the diagram The rope is rotating about end A where as end B is free S and S are the distances covered by pulse A and Pulse B respectively in rope frame before SA they cross each other If K SB Rope is rotating in horizontal plane with constant w Find the value of K 1 3

Namaste a car starts from rest and moves along the x axis with constant acceleration 5 m s 2 for 8 seconds If it then continues with constant velocity what distance will the car cover in 12 seconds sin ce it started from the rest

Q No 47 Which of the following statement is correct A iron B The pig iron is the name given to the product produced by cupola The cast iron has high tensile strength The chilled cast iron has no graphite C D The product produced by blast furnace is called cast

A cell having an emf E and internal resistance r is connected across a variable external resistance R As the resistance R is increased the plot of potential difference V across R is given by 1 Point E a v E c V 0 R D b d V V 0 R R

1 i 2 1 8i 3 2 4i 4 3 For the given situation find the acceleration 5 kg and 10 kg blocks respectively 0 H 0 3 1 1 m s 1 m s 2 0 m s 1 5 m s 3 4 m s 4 m s 4 0 m s 6 m s 5 kg 10 kg 60 N

Q No 21 The unit cells A contain the smallest number of atoms which when taken together have all the properties of the crystals of the particular metal have the same orientation and their similar faces are parallel may be defined as the smallest parallelopiped which could be transposed in three coordinate directions to build up the space lattice all of the above B C D

Q No 28 The material in which the atoms are arranged regularly in some directions but not in others is called ABCD A C D amorphous material mesomorphous material Sections crystalline material none of these

Q No 31 The coke in the charge of blast furnace controls the grade of pig iron acts as an iron bearing mineral supplies heat to reduce ore and melt the iron forms a slag by combining with impurities A B C D

Q No 20 Which of the following process of steel making is in operation at Tata Iron and Steel Works Jamshedpur ABCD A B C D Bessemer process Open hearth process Duplex process Electric process