Basic Physics Questions and Answers

1 Tick the correct option today times the Earth was very different from what it is t 1 In a modern b prehistoric 2 Early humans covered themselves with a towels b silk clothing c 3 Early humans scared wild animals away with the help of a stones b sticks 4 Growing crops meant that early humans could live a in a fixed place b in the trees c recent 5 As time passed early humans noticed that of animals skins c fire II Fill in the blanks 1 The period of time that comes after the invention of writing is called 2 Earlier early humans looked like 3 Early humans took shelter in under overhanging cliffs 4 The first crops grown by early humans were on c on the ground and walked on all fours and or grew from seeds

In a car race two cars start with velocities u and u and travel along a straight line with accelerations at and Brespectively If both reach the finish line at the same time then range of the race is Options 1 50 de Bond pormo dh ao sodg finish line 30 d 2 2 B a u u a 1 1 B a 2 11 1 a 18 u u a 2 1 1 B a do 50 a 5000000 B gdares u u a

94 The position of a particle is given by F 3ti 412 Sk Then the magnitude of the velocity of the particle at t 2 sec is 25 50 50 800 24om asgea50 F 31 41 Sk 1 2 58 sm 34 505050 1 276 m s 2 246 m s 3 255 m s 4 265 m s

The figure shows two identical parallel plate capacitors connected to a battery with switch S closed The switch is now opened and the free space between the plates of the capacitors is filled with a dielectric of dielectric constant or relative permittivity 3 The ratio of the total electrostatic energy stored in both capacitors before and after the introduction of the dielectric is Then find the value of x S VI A C B C

03 A heavy brass sphere is hung from a weightless inclastic cord and acts as a simple pendulum with its period of oscillation T The sphere is immersed in non viscus liquid of density 1 10 of the density of brass Then it will act as a simple pendulum of period mea es Jordb rds wo os ass as a T Serigs ross odforum 0500 SwoDads dood a od 1 10 50 5510 od og rosu dostum 5000 pen BA

2 Two newspapers A and B are published in a city It is known that 25 of the city population reads A and 20 reads B while 8 reads both A and B Further 30 of those who read A but not B look into advertisements and 40 of those who read B but not A also look into advertisements while 50 of those who read both A and B look into advertisements Then the percentage of the population who look into advertisements is 2019 Main 9 April II a 13 5 c 12 8 b 13 d 13 9

5 In the relation h 2Tcos a r pg where h is the height T is surface tension p density and r is the radius of a capillary tube a is angle of contact and g is acceleration due to gravity Verify the correctness of the equation

e 16 Two bodies A and B of equal masses are kept at heights of h and 2h respectively What their potential energies 17 What is the kinetic energy of a body of mass 1 kg moving with a speed of 2 m s 18 Is potential energy a vector or a scalar quantity of 100 kg is pulled up by 5 m Calculate the work done g 9 8 m s

Gourav purchased 5 pens 3 bags and 1 instrumental box and pays 16 From the same shop Dheeraj purchased 2 pens 1 bag and 3 instrumental boxes and pays 19 Ankur purchased 1 pen 2 bags and 4 instrumental boxes at 25 Based on this information answer the following questions

Two balls are projected upward simultaneously with speeds 40 m s and 60 m s Relative position x of second ball w r t first ball at time t 5 s is Neglect air resistance 1 20 m 3 100 m 2 80 m 4 120 m

While taking records of car sales in the showroom a salesman mistakenly calculated the number of cars as 530 cars The actual number of cars is 604 cars From this information find a the absolute error b percentage error For the toolbar press ALT F10 PC or ALT FN F10 Mac

The energy of the four non interacting identical fermions and bosons in one dimensional box of size a is Answer b c d D Sh 4h ma 2ma Sh 2h ma ma 10 3 2ma 2ma 2A ma 2ma A

111 A In a B decay in a nucleus a daughter nucleus that has discrete energy states is produced The daughter nucleus reaches ground state from excited state by emitting y ray B The binding energy of hydrogen nucleus is far less than the binding energy of helium nucleus 1 A False B True 3 A True B True 2 A Truc B False 4 A False B False

A stone is thrown with a velocity of 20 ms at an angle 60 with the horizontal The speed of the stone when its direction of motion makes 45 with the horizontal is Se rodo 60 so 5 o 20 ms kos 35o6 an dexir Be 3ro660 45 58 Options 1 28 28 ms 1 2 14 14 ms 1

33 Electric charges are distributed in a small volume The flux of the electric field through a spherical surface of radius 10 cm surround ing the total charge is 25 V m The flux over a concentric sphere of radius 20 cm will be A 25 V m B 50 V m C 100 V m D 200 V m

When capillary is dipped into liquid the levels of liquid inside and outside are equal The angle of contact is R RR A Zero B 90 C 45 D 60 e Your Answer

5 Two identical containers joined by a small pipe initially contain the same gas at pressure po and absolute temperature To One container is now maintained at the same temperature while the other is heated to 2To The common pressure of the gases will be 3 a Po b 4 3 Po c 5 Po d 2po

This section contains 7 multiple choice questions Each question has 4 choices A B C and D for its answer out of which ONE OR MORE is are correct Three identical cylinders each of mass M and radius R are in contact and kept on a rough horizontal surface coefficient of friction between any cylinder and surface is A force F Mgt acts on the first cylinder Mark the correct statement F umgt H 0 4 0 500 A The cylinders will start pure rolling and keep on rolling without sliding B Att 9 second slipping will start C Velocity of centre of mass of each sphere will keep on increasing D After a certain value of F angular velocity of each sphere will become constant m

When I am in lift if I consider physics then I am not rest according to the outside but I see all rest inside the lift and outside all are rest if you think by physics So I define that I am acclerated and got non innertial frame and as inside the lift all are rest according to me and vice versa I add pseudo force for valid Newton s law And result is finally valid

1 Choose the most suitable answer and fill in the blanks 1 The village town or city you live in is a a neighbourhood b community c rural area 2 There are different types of in a community a neighbourhoods b houses c buildings 3 Villages are a part of the a urban 4 Urban areas are not major activities that are carried out there a important look b alike size b local community c rural They differ in and c good age

116 The magnetic flux linked with a coil varies with time as 31 41 9 webers The induced emf at 1 2 sec is as in pobo do Dar rod 31 41 9 r sy 1 2 sec 5 505 Digger worn Jess Bebeur 1 1 V 2 6 V 3 16 V 4 10 V

Option No Option Orientation Vertical A piece of metal weighs 34 g in air When it is immersed in a liquid of specific gravity 1 24 at 27 C it weighs 32 g When the temperature of the liquid is raised to 42 C the metal piece weighs 31 g Specific gravity of the liquid at 42 C is 1 2 The coefficient of linear expansion of the metal is 25 55 55 20 34 g og 1 24 27 C 0506 ed 32g 655 42 C 6 bod ky s moj od 1 2 0 Snows 5 31 g 500 5 Options www android previousquestionpapers com www previousquestionpapers com www ios previousquestionpapers 1 www android universityupdates in www universityupdates in www ios universityupdates in 3 0 0122 K 2 0 00122 K 1 0 122 K

113 In Davisson Germer experiment the decrease of the wavelength of the electron wave was done by 1 keeping the same potential difference between anode and filament 2 decreasing the potential difference between anode and filament 3 increasing the potential difference between anode and filament 4 keeping more distance between the anode and filament

A wheel of mass 10 kg and radius 0 8 m is rolling on a road with an angular speed 20 rads without sliding The moment of inertia of the wheel about the axis of rotation is 1 2 kgm then the percentage of rotational kinetic energy in the total kinetic energy of the wheel is approximately

120 A non conducting ring of radius R has charge Q distributed over it If it rotates with an angular velocity to the equivalent current is Ragg Ko L o po Shine gamin d 360 og 2 Qo to Q 56063350 do F da Des dags Bart Qu 4 D

3 3 Qa TCE X 4 Zero 1 Parabola 2 Circle 3 Pair of straight lines 4 Hyperbola fie 6 8 The locus of points such that electric field due to a short dipole is perpendicular to the direction a dipole moment is

pject starts from rest from point P and comes to rest at point an acceleration 1 m s and for the remaining with retardation alue of distance PQ on same straight line It moves the first part of the dista 2 m s If time taken to complete the journey is 2 s then

Question Number 98 Question Id 4557344738 Question Type MCQ Display Question Number Yes Single Line Question Option No Option Orientation Vertical Certain quantity of heat is supplied to a monatomic ideal gas which expands at constant pressure The percentage of heat that is used to do work by the gas is as D b rms edoj Jan fod ca cont en go b o g J o o r 5 do Jou s Options 80 1 2 3 20 40 COOL

During an a particle decay from a nuclei at rest of atomic mass 284 the wavelength of the wave associated with the a particle is X Then the wavelength of the wave associated with the daughter nuclei must be Only one correct answer A A B C 2A 6

A particle having mass mand charge qis projected into a region having perpendicular magnetic field as shown If the width of the field d mv 29B then the deviation of charge particle as it comes out of field is Only one correct answer A 0 12 B 8 C D 0 e p

118 A galvanometer of resistance 99 2 requires 5 mA current for full scale deflection It can be converted into an ammeter of range 0 5 A by connecting a shunt resistance of 99 02 36 4 de moge rid n Bogin bid wigs Boder 5 m Dog5 x 05 000 0 5 A g s range wszedem arday doserbs ob 606 284 1 19 3 40

is instantaneous angle which joining the particle and the centre of the loop makes with the vertical as shown then identify the correct statement s related o the normal reaction N between the block and the surface A The maximum value N occurs at 0 0 B The minimum value of N occurs at 0 m for H C The value of N becomes zero at 0 for all H D Minimum value of H to complete vertical circular motion is to

time as ortional 0 12 4 1296 km 22 The position x of particle moving along x axis varies with time t as x Asin cof where A and are positive constants The acceleration a of particle varies with its position x as 1 a Ax 3 a Amx 2 a 6 x 4 a m YA

When a rubber string is stretched through a distance x the restoring force developed has a magnitude px qx x where p q and r are constants Work done in stretching the unstretched rubber string by a distance 7 is as a px qx x 5 p q Kro K535 2005 58 Options p 2 1 3 4 p 3 9 3 x 665 655 Dojo s os p q 1 4 pl q 1 58550 brengen S bado day s 1

article of mass m is released from a height H on a smooth curved surface which ends into a vertical loop of radius R as shown R 0 is instantaneous angle which joining the particle and the centre of the loop makes with the vertical as shown then identify the correct atement s related to the normal reaction N between the block and the surface A The maximum value N occurs at 0 0 B The minimum value of N occurs at 0 for H 5R C The value of N becomes zero at 0 for all H 5R D Minimum value of H to complete vertical circular motion is 3

P 555 55 55 55 ms 56 Vrms 56550 3366 300 mms 5 37 Options 1 3 Vrms Vims 3 3

A car of mass m accelerates on a level smooth road when a constant power p is delivered to it If the velocity of the car at any instant is v then its velocity will be doubled after travelling a distance m r as p Options 1 7mv 3p m r as 5 2 m go Ke 56 p s go aggan Boja D o god so 35 v you oriosos do

4 Its velocity must be constant 13 The position of a particle moving along x axis is given by x 101 21 Then the time at which it will momently come to rest is 1 O 2 2 5 s 4 10 s Tower 8 Pusa Road New Delhi 110005 Ph 011 4762345

A moves with 65 km h while B is coming ba A with 80 km h The relative velocity of B respect to A is A 15 km h C 60 km h A A Correct Not Marked By You B Incorrect Marked By You B 145 km h D 80 km h

Your JEE MAIN FULL TEST 18 starts at 10 30 am today It will be available till today midnight 12 o clock You can start the exam anytime before that ALL THE BEST An ice cube is floating in water above which a layer of lighter oil is poured As the ice melts interface and the uppermost level of oil will respectively AP Pesert Ice FIRS und A THE EN Interface A rise and fall B fall and rise C not change and not change

1 VA Va 3 VA VB 4 VVB The relative velocity of two objects A and B is 10 m s If the velocity of object A is 40 m s then the with which B is moving is assume both objects are moving in same direction 2 40 m s 4 15 m s 1 10 m s 3 30 m s

2 A plate clutch having a single driving plate with contact surfaces on each side is required to transmit 110 kW at 1250 r p m The outer diam eter of the contact surfaces is to be 300 mm The coefficient of friction is 0 4

Two balls are projected from top of a tower height 120 m one with initial upward velocity c 36 km h and other with initial downward velocit of 36 km h The speed of each ball just befor hitting the ground is Take g 10m s A 50 m s 70 m s B 50 m s 50 m s D 50 m s 5 2m s C 70 m s 50 m s A B Correct Not Marked By You

equal to R 39 If the mass of moon is M 9 81 earth find the distance of the point where gravitational field due to earth and moon cancel each between centres of earth and moon is 60 R where R is the radius of earth a 4 R c 12 R where M is the mass of b 8 R d 6 R

11 A particle of mass 2kg is moving on a circular path of radius 10m with a speed of 5m s and its speed in increasing at rate of 3m s Find the force acting on the particle a 5N b 10 N c d 14 N 12 N

A spherical shell of radius R carries a uniform surface charge do on the northern hemisphere and uniform surface charge 00 on the southern hemisphere Find the potential inside and outside the sphere calculating the coefficients explicitly up to A and B6

The charges on the two plates initially at t 0 are Q and Q Long time after closing the key the charges on the outer and inner surfaces of plate 1 are respectively C capacitance of capacitor A Q 0 IF C Q Q Ce 2 B D Q Q2 2 C Q Q Q Q 2 2 1 8 S

coil of resistance 30 and inductance 5 H is connected to a battery of emf 60 V The energy stored in the coil in steady state is n joules Find the value of n nswer

In a vessel at 101 3 kN m and 300 k the percentage relative humidity of the water vapour in the air is 25 if the partial pressure of the water vapour when air is saturated with vapour at 300 K is 3 6 kN m calculate The partial pressure of the water vapour in the vessel The humidity and the percentage humidity

The position time graph for two particles A and I are straight lines inclined at angles of 30 and 60 with the time axis The ratio of velocities VA VE is A 1 2 C 3 1 A B C Incorrect Marked By You B 1 3 D 1 3