Basic Physics Questions and Answers

In certain electronic transition from quantum level n to ground state in atomic hydrogen in one or more steps no line belonging to Brackett series is observed The wave numbers which may be observed in Balmer series is 8R 5R 9 36 3R 8R 16 9 5R 3R 36 16 3R 3R 4 16

Photon with kinetic energy of 1MeV moves from south to north It gets an acceleration of 1012 m s by an applied magnetic field west to east The value of magnetic field Rest mass of proton is 1 6 x 10 27 kg 1 71mT 2 7 1mT 3 0 071mT 4 0 71mT

A barometer with a brass scale reads 75 cms at a temperature of 16 C What will be the reading at 6 C if the coefficient of linear expansion of brass is 18 x 10 6 C and that of cubical expansion of mercury is 18 10 5 C A 73 785 cm C 76 215 cm B 73 515 cm D 76 485 cm

The plot that depicts the behavior of the mean free time t time between two successive collisions for the molecules of an ideal gas as a function of temperature T qualitatively is Graphs are schematic and not drawn to scale 1 NT T

ing velocity on a frictionless road suddenly enter on to a frictional road and then travels a distance S before coming to rest The coefficient of frictia

tion 23 Three tuning forks of frequencies 200 203 and 207 Hz are sounded together Find out the beat frequency Solution y 0 so y y 0 Y2 10 Two tuni a Be b Mi N

Four vectors PQ QR PS and SR are connected as shown in figure such that S is the mid point of PR and PQ QRI then which two vectors are NCERT Pg 66 equal RA 1 PQ and QR 3 PQ and PS Q S P 2 PS and SR 4 Both 1 2

4 Three points masses each of mass m are placed at the corners of an equilateral triangle of side l The moment of inertia of the system about an axis pasing through one of the vertices and parallel to the side joining other two vertices will be

A car moving with certain velocity on a frictionless road suddenly enter on to a frictional road and then travels a distance S before coming to rest The coefficient of friction between the road and the tire is The time in which the car can cover the distance S is proportional to A L B C J D

The coordinates of centre of mass of a uniform flag shaped lamina thin flat plate of mass 4kg The coordinates of the same are shown in figure are 0 3 0 0 1 2 1 0 1 1 25m 1 50m 3 0 75m 0 75m 2 3 2 2 2 1m 1 75m 4 0 75m 1 75m

An Infinite sheet having surface charge density is placed in front of a metallic charged sphere of charge Q and radius R a shown in the figure such that surface of metallic plate is perpendicular to the line CO where O is the centre of the plate T separation between the sheet and the centre of the metallic sphere C is 2R Answer the following questions based on the given situations 1 2R O 6 280 80 P Electric field at point P2 just outside the sphere 280 KQ R C greater than Metallic sphere haveing charge Q 6 280 P

5 The excess pressure inside the first soap bubble of radius R is two times that inside th second soap bubble of radius R The ratio of volumes of the first bubble to that of secon bubble is R R A 1 2 B1 8 C 1 1 D 1 4 3 4

The dimension of stopping potential V in photoelectric effect in units of Planck s constant h speed of light e and Gravitational constant G and ampere A is 1 h G3 2 c1 3 A 1 2 h 2 3 c 1 3 G4 3 A 1 3 h1 3 G2 3 c1 3 A 1

10 Two unlike charges attract each other with a forc of 10N If the distance between them is doubled the force between them is 1 40N 2 20N 3 5N 4 2 5M

A simple pendulum performs simple harmonic motion about x 0 with an amplitude a and time period T The speed of the pendulum at x a 2 will be Question Type Single Correct Type 1 2 a T 3 a T

4 25 A non relativistic charged particle flies through the electric field of a cylindrical capacitor and gets into a uniform transverse magnetic field with induction B In the capacitor the particle moves along the arc of a circle in the magnetic field along a semi circle of radius r The potential difference Ans applied to the capacitor is equal to V the radii of electrodes are equal to a and b with a b Find the velocity of the particle and its specific charge q m Ans h V A 1 4 3 ene ma 4 3 xf as

A copper ball of radius r travels with a uniform speed v in a viscous fluid If the ball is changed with another copper ball of radius 2r then new uniform speed will be Question Type Single Correct Type 1 V 2 2v 3 4v

A particle A of mass mis moving with velocity vo collides elastically with an identical particle Bat rest After collision velocity of particle B will be OPTIONS MARK FOR REVIEW CLEAR SELECTION A Vo B Yo 2 O B

Two identical capacitors each of capacitance 5 F are charged to potentials 2kV and 1 kV respectively The ve ends are connected together When the ve ends are also connected together the loss of energy of the system is Question Type Single Correct Type 1 160 J 20 J

13 For the RLC series circuit shown which of these statements is true R 000000 C 1 The source does no net work Energy lost in R is compensated by energy stored in C and L 2 The current through C leads current through L by 90 3 The current through C is 180 out of phase with the current through L 4 All energy is dissipated in R

Find the effective resistance of the infinite grid between A and B 1 www 11 1 O 3 3 4 2 3 6 www O 3 3 40 4 3 6 O2 3 42 4 3 6 O 2 3 42 3 3 6 1 www www A 1 www www 1 www B 1 www www www www

When wave enter from one medium to another medium which quantity remain unchanged Question Type Single Correct Type 1 Frequency 2 Wavelength 3 Wave speed A Amplitude

Outer sphere given a charge and inner is earthed b R Q Uncharged R qu P b or your a R a No induced charge as E 0 E 0 Fre When K is closed Vin 0 so a negative charge appears on its surface SUAL CANIN 2 28 7 2021 06 27

od 81 mass mand lengt moving between perpendicular smooth walls as shown When rod is at angle 8 with horizontal its end B is moving right with speed v The speed of end A is y A 3 vtane vcote B X

If the coefficient of restitution is 0 6 then collision is OPTIONS CLEAR SELECTION MARK FOR REVIEW O A Perfectly elastic collision B Perfectly inelastic collision C Inelastic collision

A body of mass 1 kg is suspended from free end of massless spring of natural length 1 m If mass is suddenly released from rest spring stretches upto a vertical distance of 40 cm the potential energy stored in the spring at this extension is g 10 m s OPTIONS CLEAR SELECTION OA 2 J B 8 J MARK FOR REVIEW

A particle moving with a velocity v in x direction has an inelastic collision with a wall moving in opposite direction with a speed V and coefficient of restitution is e If the speed of the ball remains same after collision than V is modulus value L 1 e 324 3 17 2 4 1 2e Le

led with t slowly tuning at the city of total ll be 382 Hz d 7 13 A second harmonic has to be generated in a string of length L stretched between two rigid support The point where the string has to be plucked and touched are NCERT XI Pg 381 V L 1 Plucked at and touch at 2 2 Plucked at and touch at 3 Plucked at 4 Plucked at 1 2 and touch at and touch at 3L 8 3L A 1 2 3 Maps sitar strings A and B playing a news htly out of tune and produce beats of quency 5 Hz When the tension in the ing B is slightly increased the beat quency is found to reduce to 3 Hz t quency of string A is 427 Hz The orig equency of string B is INCERT XI P 1 422 Hz 424 Hz 3 430 Hz 432 Hz

Forces of magnitudes 6N and 4N are acting on a body Which of the following can be resultant of the two A 11N B 2N C 10N D IN If A 1 x 3k and B 21 k then the value s of x for which the dot product of A B is

2 Which pair s have same dimensional formula formula for Torque Force Perpendicular distance Impulse Force Time Angular momentum Mass velocity perpendicular distance hc Energy c is speed of light is wavelength 2 Force x length Elastic modulus Area x Change in length Force Area A Energy and torque B Force and impulse C Angular momentum and Plank s constant D Elastic modulus and pressure Pressure

3 0 34 mm 1 5 mm 4 6 8 mm 30 mm A pipe 30 cm long is open at both the ends Which harmonic mode of the pipe resonates with 1 1 kHz source v 330 m s 1 First 2 Second 3 Third 4 Forth NCERT XI Pg 382 A progressive wave is represented by y 2 sin 100nt 2x where x and y are in cm and it is in second The maximum particle velocity and wave velocity respectively are INCERT XI Pg 3731 BAY Toprium 9 2 y 0 4sin 2 t 2 X 3 y 0 4 sin 2 t 2 4 y 0 4 sin2 t 1 A sound is produced by plucki a musical instrument then NCER 1 The velocity of wave in stri the sound velocity in string 2 The frequency of wave ins

17 A horizontal wire is lined up in the North South direction A compass needle is placed above the wire When the current is turned on the North Pole of the Compass is deflected towards the West In which direction are electrons in the wire moving A East C North B West D South barns

1 507 Hz 2 502 Hz 3 517 Hz 4 522 Hz 12 The equation of a stationary wave along a stretched string is given by cos 40 nt in where x and y are cm and t is in second The separation between two adjacent nodes is 2 X 3 y 5 sin 1 1 5 cm 3 6 cm NCERT XI Pg 379 2 3 cm 4 4 cm XI Pg 386 1 0 2 3 10 4 15 A railway engine whistlin frequency moves with a goes past a stationary c beside the railway track of the sound heard by o against time t Which of t best represent the varia frequency with time N

A projectile is fired wth a speed u at an angle e above the horizontal field The coefficient of restitution between the projectile and field is e Find the position from the starting point when the projectile will land at its second collision 1 e u sin e 2 1 e u sin 20 1 e u sin 0 cos 0 3 4 1 e u sin 20

Potential energy of a particle as a function of its displacement from origin is given by U x bx The body is in stable equilibrium at origin if bis 1 1 2 2 3 3 4 both 1 and 3

If A 2 i k and B 1 2 2k find the magnitude of component of A B along B If three forces F 6a 8a N F 8b 3b N and F 26i 19 N acting simultaneously on a body keep it in translational equilibrium determine numerical value of b a

the A cylinder is wrapped around its lateral surface by a rope as shown figure The rope is moved upwards such that cylinder does not fall from its initial position Initially it was at rest What is the acceleration of the rope mg Og 02g O 2 2

Marks 4 Marks 0 In all other cases the correct numerical value is entered a 1 i 2 3k B 31 4 a 1 k value of 3a if ALB C Jah 2

5 5 If y 8 sin 8 then what is the approximate value of y Choose the appropriate option TU T A 1 TU 180 B 2 270 TU 270 90 If unit of length mass and time each be doubled the unit of work is increased to C 2 D 1

marks A particle describes circular orbit under the influence of an attractive force directed towards a point P on the circle The magnitude of force can be written as kr where k is some constant and r is the distance from point P Here n can be

Vectors A and B are given as A 101 2tj and vector B 51 5 Find the time when A perpendicular to B A 4s B 6s T TA 1 C 2s 1 D 5s

A ball of mass 1kg is falling from a height 4 m strikes the ground and moves through 1m penitrating the ground What is the average resistive force on the ball from ground 1 5 N 2 10 N 3 50 N 4 20 N

A body accelerates uniformly from rest to a velocity of 1 ms in 15 seconds The kinetic energy of the body will be joule when time t equal to take mass of body equal to 1 kg 010 s 04s 0 12 s 085

In a hydrogen atom an electron is revolving in a circular path of radius 5 1 x 10 11 m with frequency of 6 8 x 1015 Hz The equivalent magnetic moment is 8 9 x 10 24 Am O 6 2 x 10 25 Am O 12 6 x 10 24 Am O 5 38 x 10 25 Am

A current of 0 01 A flows through a potentiometer wire of cross sectional area 10 6 m If the specific resistance of the potentiometer wire is 10 7 ohm m then the potential gradient will be YOU A O 10 1 V m B 10 V m c 10 V m

When a man stands on a turn table stretching with two equal loads in hand and rotates Then he folds his arm Which of the following statement is correct O Linear momentum is conserved O Time period increases Angular momentum increases Angular velocity increases

The potential gradient along the length of a uniform wire is 10 V m The length of the potentiometer wire is 4m What is the potential difference across two points on the wire separated by 50 cm A 2 5 V YOU B 5 0 V C O 1 25 V

Which of the following is perpendicular to i j k A i j k B i i k C i j k D none of these Vectors A and B are given as A 101 2t and vector B 51 5 Find the time when A

q R iv A point charge is placed at some distance from sphere as V 0 in Uncharged metallic sphere a REat 0 0 net q ind O V pt P xx b A non uniformly distributed charge is induced on the sphere q ON Qind 0 FY AR C 2021 06 27 14 09

A prism of prism angle A 60 and refractive index n2 is placed in a liquid of refractive index n A light ray is incident on face AB at constant angle of incidence i and it emerges at surface AC at angle of emergent e Some how n is increasing at rate N and n2 is increasing at rate N2 Choose the correct option s A If C If n N n N N n then e is increasing then e is decreasing i constant PRICI n B If D If A N N n ZA 60 T2 N then e is decreasing N n n1 then e is increasing B