Basic Physics Questions and Answers

2 a nuclear fusion process the masses of fusing nuclei be m and and the mass of product nuclei be m then m stion ape 1 m m m 2 m m m 3 m m m 4 m 11

a 0 b 45 3 Two simple pendulums of length 0 5 m and 20 m respectively are given small linear displacement in one direction at the same time They will again be in the phase when the pendulum of shorter length has completed x oscillations where k is a 1 b 3 d 5 c 2 500 m of helium at 27 C 3

A point charge q is placed at a distance 2r from the centre O of a conducting neutral sphere of radius r Due to the induced charge on the sphere the electric potential at point P on the surface of sphere kq is x volt Then find the value of x If 18 volt I 2r TH DI O r P 1

2 Two similar coils are kept mutually perpendicular such that their centres coincide At the centre find the ratio of the magnetic field due to one coil and the resultant magnetic field through both coils if the same current is flown 1 2 1 2 3 1 3 1 2

An air bubble in sphere having 4 cm diameter appears 1 cm from surface nearest to eye when looked along diameter If alg 1 5 the distance of bubble from refracting surface is Question Type Single Correct Type 1 2 3 4 1 2 cm 3 2 cm 2 8 cm 1 6 cm

A particle having charge q and mass m moving with velocity Venters a region of magnetic field B and electric field The motion of the particle will be Given V B and E are parallel Non uniform motion along a curved path Non uniform motion along a straight path O Uniform circular motion O Along a helix

Two bodies A and B of masses 20 g and 15 g respectively are on a horizontal plane A is at rest and B is moving at 5 ns to the left B collides with A and as a result A starts moving at 3 m s to the left What is the final velocity of B 5

21 A uniform but time varying magnetic field B t exist in a circular region of radius R and is directed into the plane of the paper The magnitude of the induced electric field at distance r from the centre of the circular region varies as question paper 3 h Work E XX R XX B 1 X X xOx R X X X E E h h 1 2 R R X X X X XXX 4 XTX E R

A proton of charge e and mass m enters a uniform and constant magnetic field B B with an initial velocity V Vox Vor Which of the following will be correct at any later time t A x component of velocity of the proton will be V cos qBt m B y component of velocity will be Voy cos qBt m C z component of velocity will be Voy sin along direction qBt m D x component of velocity will remains unchanged

nC m Let there be a non conducting infinite large sheet of charge of surface charge density 36T uncharged conducting spherical shell of radius 20 cm is placed in front of sheet A point charge 6mC placed at centre of the shell Force on point charge due to shell is x mN Find value of x

A metal block of mass m slides on a horizontal surface which is lubricated with oil Assume that the initial velocity of the block is v at x 0 and a velocity dependent viscous resistance is working on the block given by F v kv 2 Show that the maximum distance travelled by the block is given by 2m v 1 2 k

The photoelectric work function 1 Is different for different materials 2 Is same for all metals 3 Depends upon frequency of the incident lig 4 Depends upon intensity of the incident ligh

The photoelectric threshold for a certain metal surface is 330 What is the maximum kinetic energy of the photoelectrons emitted if radiations of wavelength 1100 are used 1 1 eV 2 2 eV 3 7 5 eV 4 No electron is emitted

A particle starts from rest at t 0 and moves in a straight line with an acceleration as shown below The velocity of the particle at t 3 s is Kerala PET 2008 Acceleration m s a 2ms 1 1 c 6 ms e 1ms 1 4 2 4 TI 1 2 3 4 Time s b 4ms 1 d 8 ms 1

5 Two trains each of length 100 m moving in opposite directions along parallel lines meet each other with speeds of 50 km h and 40 km h If their accelerations are 30 cm s and 20 cm s respectively find the time they will take to pass each other

6 A box of mass 20 kg is sliding along the inclined plane which makes an 60 with the ground What is the magnitude of the Normal Force Assume g 10m s A 100 N B 173 2 N C 141 4 N D 200 N F N F F 4

a photoemissive cell with executing wavelength the fastest electron has speed v If the exciting wavelength is changed to 3 4 the speed of the fastest emitted electron will be da A v 3 4 2 B v 4 3 2 C Less than v 4 3 D Greater than v 4 3

A particle is moving on a straight line with a speed of about 0 5 m s To measure its speed points are marked on the line of motion which are exactly separated by 5 mm To have an accuracy of 99 in the determination of speed the minimum least count of the measuring clock is nx 10 4 s Find value of n

Find the velocity and the position as functions of the time for a particle of mass m which starts from rest subject to the following force function F x Fosinct where Fo and c are positive constants 12 5 2 51

The electric field in an electromagnetic wave is given by E 50 N C sino t x c Find the intensity of the wave 1 3 3 W m 3 2 4 W m 2 4 8 W m 4 3 9 W m Telegran

A potential difference of 600 V is applied across the plates of capacitor the separation between the plates is 3 cm An electron is projected parallel to plates with velocity 2 x 105 m s moves undeflected The magnitude of magnetic field between capacitor plates is 0 4 T 0 3 T 0 2 T 0 1 T

A wheel having moment of inertia 12 kg m about an axis is rotating at 180 rpm If the wheel is stopped in a time of 10 second how much average retarding torque is applied 14 5 Nm 22 6 N m 36 5 Nm

A rod of mass 3 kg with length of 2 m is rotating about an axis perpendicular to its length and passing through its centre of mass If the angular speed of the rod is 10 rad s then what is its rotational kinetic energy O 50 J O 100 J 150 J 200 J

spring as shown in figure The magnitudes of acceleration of A and B immediately after the spring is cut are respectively Junge 3m m LE 3m g g g g 3 3 8 0 0 m g pol m g Two blocks of masses 3m and m respectively are connected by a massless and inextensible string The whole system is suspended by a massless spring as shown in figure The magnitudes of acceleration of A and B immediately after the spring is cut are respectively 3 g 6 0 g g g g g 3 3 pol m g 3

42 Pendulum A is x cm shorter than a seconds pen dulum and pendulum B is x cm longer than the seconds pendulum The ratio of their time periods is 3 4 The length of the pendulum with higher frequency is

A beam of unpolarised light of intensity is passed through a polaroid A and then through another polaroid B which is oriented so that its principal plane makes an angle of 45 relative to that of A If intensity of the emergent light is then value of Nis 4 10 N y

An ocean going vessel uses sonar to measure the depth of the ocean If a sound wave sent from the ship bounces off the ocean floor 525 0 m below and returns to the ship after 0 875 seconds then what is the speed in m s of the sound waves in water Enter a numerical answer with three significant figures

A mass m moves with a velocity v and collides inelastically with another identical mass After collision the 1st mass moves with velocity v 3 in a direction perpendicular to the initial direction of motion Find the speed of the 2nd mass after collision 1 V 3 2v 3 2 3 v 4 v 3 Before collision v v3 After collision 1000

A particle moves along a straight line x At time t 0 its position is at x 0 The velocity V of the object changes as a function of time t as indicated in the figure t is in seconds V in m sec and x in meters a What is x at t 3 sec b What is the instantaneous acceleration in m sec at t 2 sec c What is the average velocity in m sec between t 0 and t 3 sec d What is the average speed in m sec between t 1 and t 3 sec V m sec 3 2 1 0 1 2 3 t sec 2

The position x of a particle w r t time t along x axis is given by x 9t t where x is in metre and t in second Find a Maximum speed along x direction b Position of turning point c Displacement in first ten seconds d Distance travelled in first ten seconds

A boy of mass 20 kg is standing on a 80 kg free to move long cart There is negligible friction between cart and ground Initially the body is standing 25 m from a wall If he walks 10 m on the cart towards the wall then the final distance of the boy from the wall will be 1 15 m 2013 3 15 5 m 2 12 5 m 4 17 m

A proton of mass m and charge e is moving in a circular orbit in a magnetic field with kinetic energy 1 MeV The energy of a particle so that it can revolve in the path of same radius is 0 5 MeV O 1 MeV 2 MeV 4 MeV

According to the Bohr model the energy levels of a hydrogen atom can be found by making two assumptions i The electrons move in a circular orbit and ii The angular momentum of the electron in the 7 th th energy level is quantised to have a value The levels calculated with a nuclear charge Ze deals with a single electron in the orbit are called hydrogenic levels Assume that the two electrons in the ground state of a helium atom occupy the corresponding lowest hydrogenic level Now match Column I with Column II and select the correct option from the choices given below the column A The minimum repulsive energy between the two electrons would then be If for a hydrogen atom ionisation temperature is T the temperature at which he atoms ionise B C completely both electrons having left off the atom would be Energy required to remove two electrons from helium atom must be greater than A D Column I A 2 B 4 C 1 Your Answer A 1 B 4 C 3 A 1 B 3 C 2 A 2 B 3 C 1 Correct Answer Column 1 54 4 eV 2 27 Z eV 3 87 4 4T

equivalent of 16 F with breakdown voltage of 1000 V how many minimum number of capacitance marked 8 F 250 V are required 1 16 2 32 3 2

26 A current loop consists of two identical semicircula parts each of radius R one lying in the x y plane and the other in x z plane If the current in the loop is i The resultant magnetic field due to the two semicircular parts at their common centre is AIPMT Mains 2010 Hoi 1 2 2R 2 Hoi 2 R Hoi

An electromagnetic wave going through vacuum is described by E E sin kx oot B B sin kx cot Then 1 E B ok 3 Ek B00 E 2 B 0 k 4 E Bok

dashed line A rigid square loop of side length 1 carrying an electric current is held motionless on a frictionless horizontal tabletop A uniform magnetic field pointing upwards is switched on everywhere to the left of the shown in the figure and then the loop is released Considering different lengths of the side segments x and y x y which of the following conclusions can you make a If x 1 2 6 If x 2 1 c If x 2 as and y and y and y 1 and y the loop starts rotating anticlockwise 2 1 the loop starts rotating anticlockwise 2 1 2 the loop starts rotating clockwise 1 x 1 1 2 the loop starts rotating 1 more information is required to decide which way 9 2 of radii a and b are separated by a large is the force of

In a vernier callipers with no zero error 7th division of main scale coincides with 10th division of vernier scale when nothing is kept between the calipers Take 1 MSD Imm When a rod of length is kept between the calipers it is found that zero of the vernier lies between the 9th and 10th divisions of main scale and 4th division of the vernier coincides with 12th division of main scale B 10 2mm D vernier constant 0 3mm A 9 2mm C Least count 0 3mm

Q 21 A current carrying closed loop in the form of a right angle isosceles triangle ABC is place in a uniform magnetic field acting along AB If the magnetic force on the arm BC is F the force on the arm AC is A Option A Option B Option C Option D PRAN 2F F

3 4 Q 34 Four cells of emf and internal resistance as shown are connected in parallel The equivalent cell between A and B will have internal resistance and emf as uestionpaper A 1 2 1 3 9 1V gh Work 1 V 2 V 3 V 4 V 618 a wwww wwwwww 192 wwwwww 192 192 2 2 2V 4 2 2V 4 B

B A cylindrical conductor of radius R is carrying a constant current The plot of the magnitude of the magnetic field B with the distance d from the centre of the conductor is correctly represented by the figure NEET 2019 B 1 3 Rd B VAA ISC Rd 2 4 B B R d R d

Q 11 The potential energy of a system increases if work is doneyu Option A Upon the system by a conservative force Option B Option C Upon the system by a non conservative force By the system against a conservative force Option D Correct Option C By the system against a non conservative force LIVE

The displacement of a particle in SHM varies according to the relation x 4 cos t sinnt The amplitude of the particle is Question Type Single Correct Type 1 2 3 4 4 4 2

5 In the circuit shown choose the correct option All batteries are ideal 10 V 4 V 392 1 Power dissipated in 3 2 resistance is 12 W 2 Current in the circuit is 6 A 3 Power supplied by 10 V battery is 40 W

The diameter of a brass metal bob is fo und to be as 1 92cm The mass of the Bob is measured to be 29 150g The de nsity of material in kilogram per metre cube to correct number of significant fi qures is

3 Three equal impedances each having a resistance of 2502 and reactance of 400 an connected in star to a 400V 3 phase 50Hz system Calculate i the line curren ii power factor and current iii power consumed

The figure shows a system consisting of i a ring of outer radius 3R rolling clockwise without slipping on a horizontal surface with angular speed and ii an inner disc of radius 2R rotating anti clockwise with angular speed w 2 The ring and disc are separated by frictionless ball bearings The system is in the x z plane The point P on the inner disc is at a distance R from the origin where OP makes an angle of 30 with the horizontal Then with respect to the horizontal surface 20 3R Z 2R 30 A the point O has a linear velocity 3Rwi B the point P has a linear velocity R C the point P has a linear velocity 13 4 D the point P has a linear velocity 3 Rwi Rai 3 4 Rak 3 Rak 4 3 3 Ravi Rask 4

Find the maximum kinetic energy in eV of the photoelectron liberated from the surface of lithium work function radiation 2 15 eV by electromagnetic whose electric component varies with time as E a 1 cos wt coswot where a is a constant w 12 1014 rads 1 and wo 3 6 10 5 rads 1 h 6 6 10 34 in Sl units

34 An electron and a proton are held 2 m apart The midpoint between the electron and the proton sets the origin of a co ordinate system with the x axis pointing toward the proton a A second electron is moved to the origin from infinity How much work does this take b Keeping the second elec tron fixed at the origin a third electron is sent toward the ori gin with a velocity of 400 m s from the location 0 m 10 m How close does this electron get to the origin

distance from a long line charge linear charge density 2 as shown in the figure The value of electric force experienced by dipole varies with distance ras 1 4 2 1 211Eor