Basic Physics Questions and Answers

If A i 2 3k and B 21 j 2k then find a vector whose magnitude is equal to component of A along B and direction is along A 2 2 2 2k 14 A B C D 2 2 i 3k 14 2 1 2j 3k 14 2 2 3k 14

8 The diagram shows the PV diagram of a process carried out with a certain quantity of oxygen IFV 5 V find the volume till the gas absorbs heat 12 V and V B P S B N W 7

A point source of light is fixed on a horizontal plane at a distance 7m from a vertical fixed wall A long cylinder of radius R 3m starts moving towards the point source with constant velocity vo 3m s The sphere was initially in contact with wall A Initial velocity of shadow of topmost point of sphere on wall is 54m s B Initial velocity of shadow of topmost point of sphere on wall is 36m s C Initial position of shadow of topmost point of sphere on wall is 24m 1 D Bright area on wall will disappear after sec 3

PHYSICS A point source of light is fixed on a horizontal plane at a distance 7m from a vertical fixed wall A long cylinder of radius R 3m starts moving towards the point source with constant velocity vo 3m s The sphere was initially in contact with wall A Initial velocity of shadow of topmost point of sphere on wall is 54m s B Initial velocity of shadow of topmost point of sphere on wall is 36m s C Initial position of shadow of topmost point of sphere on wall is 24m D Bright area on wall will disappear after 3 sec

A gaseous system changes from state A P V T to B P V T B to C P V and finally from C to A The whole process may be called 1 Reversible process 2 Cyclic process 3 Isobaric process 4 Spontaneous process

If A physical quantity x is given as x yw A Pwa where F is force A is area x is F B x distance and P is power then match following list List I Q than P Dimension of is 1 M L T If y is velocity S 2 R than dimension of wis If y is velocity dimension of a is If dimensionless 00 is List II than dimension of y is 2 MOLITO 3 M3 2L1 27 2 4 M LOT 2 2 2 1 R B P 2 Q 1 R 3 S 4 C P 1 Q 3 R 2 S 4 D P 4 Q 2 R 3 S 1

If A 1 2 3k and B 21 2k then find a vector whose magnitude is equal to component of A along B and direction is along A A B C D 2 21 2 2k 14 2 21 5 3k 14 2 1 25 3k i 14 2 i 25 3k

19 S Two beads each of mass m are free to move only along horizontal direction on a frictionless wir as shown in figure Another mass 2m is attached to both of them by a massless string At the give instant H A B List I P Acceleration of 2m mass Q Acceleration of the first bead with respect to the second R Tension in string m Codes Normal Reaction on bead m P 3 3 1 4 R22 S T 4 1 2m m T List II 1 g 1 cos 0 2 g cos 0 3 g sin 0 4 g sin20

0 A closed organ pipe and an open organ pipe of equal length give 2 beats per second when sounded in their fundamental modes When the length of closed organ pipe is doubled and that of open organ pipe is halved and again they are vibrated in their fundamental modes then the number of beats per second is 1 2 2 4 3 6 4 7 1

40 Physics A simple microscope has a focal length of 5 cm The magnification at the least distance of distinct vision is Question Type Single Correct Type 1 2 1 English 5

Q 41 If a body of mass m is taken out from a point below the surface of earth equal to half t radius of earth R to a height R above the earths surface then work done on it will be a 5 6 mgR c 7 8 mgR b 6 7 mgR d 8 9 mgR

A small block of mass 490 g rests close to the left wall of a box of equal mass Length of the box is 40 cm The box is placed on a horizontal floor lubricated with oil Force of viscous friction of the lubricating oil is given by equation F ku where k 0 5 kg s and is velocity relative to the floor There is no friction between the block of the box If the block is given a velocity 10 m s towards many times will the block collide with walls of the box and how far will the box move of the box and the floor the right how Creative

A diwali rocket moves vertically with constant acceleration of 5 ms 2 After some time its fuel exhausted and then it falls freely If maximum height attained by the rocket is 60m Then find its speeds when the fuel is just exhausted g 10ms A 10 ms C 30 ms 1 B 20 ms D None of these

NEET PHYSICS Q 132 For photoelectric emission from certain metal Q 132 the cutoff frequency is v If radiation of frequency 2v impinges on the metal plate the maximum possible velocity of the emitted electron will be m is the electron mass 1 hv m 3 All India Major Test Series Phase I II Major after ng eft angen vi TENT 2 hv m 2 2hv m 4 hv 2m A 1 hv m 3 2 hv m

A moving coil galvanometer shows deflection of 100 divisions when 20mA current is passed through it If the resistance of the galvanometer coil is 509 find the voltage sensitivity of galvanometer 1 0 1 division mV 3 3 division mV 2 5 division mV 4 10 division mV

Q 127 A potentiometer wire of length L and a resistance r are connected in series with a battery of e m f E and resistance r An unknown e m f E is balanced at a length of the potentiometer wire The e m f E will be given by 1 LEor r r Enr l 2 LE or 1 Egl Q 127 L stoffsh r fanzit Sta 1 0

4 Find the magnitude of the electric field at a distance of R 3 from the center of sphere of radius R with total charge Q uniformly distributed throughout its volume A Q 2 6TE R B Q 4 E R C Q 127 R D Q 8 E R

Two particles are oscillating along two close parallel straight lines side by side with the same frequency and amplitudes They pass each other moving in opposite directions when their displacement is half of the amplitude The mean positions of the two particles lie on a straight line perpendicular to the paths of the two particles The phase difference is a b 0 d T Mains 2011 c P O 0 2T

If two bodies attract each other by electric force then 1 Both may oppositely charged 2 One may neutral 3 Both may neutral 4 All statements are true af fe 1 fa 2 3 R fa am GRI 31 f n da

4 G 120 Two non mixing liquids of densities p and np n 1 are put in a container The height of each liquid is h A solid cylinder of length L and density d is put in this container The cylinder floats with its axis vertical and length pL p 1 in the denser liquid The density d is equal to 1 1 n 1 p p 3 2 n 1 plp 2 2 n 1 p p 4 1 n 1 p p Q 120 1 8 G 3 3 4 G atza fora P n 1 B 1 1 n 1 plp 3 2 n 1 p p f 2 4 G 3 4 G The efficiency of an ideal heat engine working Q 121 a fore any between the freezing point and boiling point of wate La afe PL p 2 2 n 1 p 4 1 n 1 p

3 A uniform rod of mass M and length L is free to rotate about one of its ends in a vertical plane If it is released from a horizontal position then what will be tangential acceleration of its centre of mass when it becomes vertical 1 Zero g 3 3 2 4 MIN 2 3 g g

8 Conductivity increases in the order of b Al Cu Ag d Ag Cu Al a Al Ag Cu c Cu Al Ag 9 By mistake a voltmeter is connected in ammeter in parallel When the 15 A

A given number of cells each of same e m f and internal resistance r are to be grouped in such a way that the current flowing through external resistance R is maximum Which of the following statement is correct a series combination ifR r and parallel combination ifR r b series combination ifR r and parallel combination ifR r c mixed combination for series combination if R r and parallel combination if R r

3 1332 hz 4 1372 Hz 3 1332 hz 25 The electric field in a certain region is acting Q 125 fe radially outward and is given by E Ar fun an A charge contained in a sphere of radius a centered at the origin of the field will be given by 1 Apa 3 Aa 2 4 Aa 4 4x6 Aa fa a t site for 1 Asga 3 Aa 2 1454 Hz 4 1372 Hz faga sien gri faven 8 E Ar me forer f a 2 4 Aa 4 4Aa

Q 155 If electron in coolidge tube are accelerated Q 155 af 100 through a potential difference of 100 V then the minimum wavelength of the continuous X rays produced will be about 1 13 2 nm 3 14 5 A 2 12 4 A 4 12 4 mm ft for a fait f te 1 13 2 nm 3 14 5 A 2 12 4 A 4 12 4 nm

ET PHYSICS 3 A particle is executing a simple harmonic Q 123 motion Its maximum acceleration is a and maximum velocity is Then its time period of vibration will be 1 2n a 3 a B All India Major Test Series Phase I II Major Test 27 21 28 05 2 B a 4 8 a fra en af B gera aterat madara t 1 2x a 3 a p 2 B a 4 B a

NEET PHYSICS i f All India Major Test Series Phase l II Major Test 27 21 28 05 2020 Q 115 A particle of unit mass undergoes one Q 115 dimensional motion such that its velocity varies according to v x Bx 2n where and n are constants and x is the position of the particle The acceleration of the particle as a function of x is given by 1 2n x 48 1 2 28 2 1 3 2n 4n 1 4 2n x 20 1 Rafda sta t 2n if v x Bx viet B en n ferix Ref X Profe for 1 2n8 x 4 1 3 2n e 4n 1 2 28 2n 1 4 2n x 2n 1

22 The mean free path of molecules of a gas Q 122 af faal radius r is inversely proportional to 1 r 2 3 4 12 5 a 1 r 3 2 r

Question 22 A single phase transformer has 500 turns on primary winding and 1000 turns on secondary winding If the primary voltage is 100 V what will be the secondary voltage 100 200 300

f e 1 79 A particle move in a plane according to the law v vi bo cos ootj If the particle is at the origin at t 0 find the equation of its path y f x and its distance from the origin at t 3w 2 Ans y b sin w X Vo 9 vow b sin

A block of mass m 4 kg is kept on a rough surface of 0 25 At t 0 an external force F t that varies linearly with time starts acting on the block The force acts for a duration of 8 sec only and F t 8 0 N If the block starts moving at t 2 sec and finally stops at t 11 sec then find the time in sec instant when velocity acquired by the block is maximum m F

A particle which is simultaneously subjected to two perpendicular simple harmonic motions represented by x a cos ot and y a cos ot traces a curve given by 2014 A y y C C a a2 O y a2 a O Hot X X D a a2 O a y a2 O X X

2 4 A turn of radius 20 m is banked for the vehicle of mass 200 kg going at a speed of 10 m s Find the direction and magnitude of frictional force acting on a vehicle if it moves with a speed a 5 m s b 15 m s Assume that friction is sufficient to prevent slipping g 10 m s

22 The magnetic induction and magnetising field intensity in a sample of magnetic material are B and H respectively The magnetic susceptibility of the material is 1 MOH 3 B 1 H B 2 MOH Van Blog bn log bns M MOH 4 B 1 1

126 The potential difference VA V between the Q 12 points A and B in the given figure is 202 VA A I 2A 3V wwwwww 10 1 6 V 2 9 V 3 3 V VB B 4 3 V

18 Consider the situation shown in q the figure The capacitor A has a charge q on it whereas B is uncharged appearing on the capacitor B a after the switch is IIT JEE 2001 long time closed is a zero c a The charge A b q 2 d 2a ITETITEL S Fig 8 114 B

A spherical surface of radius of curvature R separates air refractive index 1 0 from glass refractive index 1 5 The centre of curvature is in glass A point object P placed in air is found to have a real image Q in the glass The line PQ cuts the surface at a point O and PO OQ The distance PO is equal to Question Type Single Correct Type 1 2 R 3 R

4 84 The tennis ball may leave the racket of a top player on the serve with a speed of 65 m s If mass of the ball is 0 06 kg and is in contact with the racket for 0 03 sec what is the average force n the ball

0 An alternating emf of 100 V 50 Hz is applied across a 10 uF capacitor and 100 resistor in series Calculate the reactance of the capacitor the current flowing and the average power supplied Ans 318 22 0 30 A 9 0 W

Two spheres A and B of mass m each were fired vertically from the ground with different initial velocities at different times When sphere A reached its summit sphere B with an upward velocity of 5 6 m s created a head on collision with A The impact caused sphere A to break into two pieces each of mass m 2 Knowing one piece reached Point C and the other piece reached point D after the collision determine a the velocity of sphere B after the collision b the angle and the speeds of the two pieces after the collision and c the force exerted by sphere A on B if the collision occurred in 0 001 s C 0 088 m 60 B 0 150 m D

2 102 A sphere the density and specific heat of whose material are respectively d and s is suspended in an enclosure The radius of the sphere is r and the temperature difference 40 between the sphere and surroundings is small If the temperature of the surroundings is 0 0 then the rate of fall of temperature of the sphere will be 1 400 40 rds 400 40 rds 2 4 12040 rdse 1200 40 rds Q 102 ret ant faff fra 40 1 3 400 40 rds 400 40 rds 2 12040 rdse 1200 A0 rds and

2 39 A body with zero initial velocity slips from the top of an inclined plane forming an angle a with the horizontal The coefficient of friction u between the body and the plane increases with the distance s from the top according to the law u bs After what distance the body will stop Ans 2 tan a b

F F FF F force on left drum upward F Ro 2Ro BW force on right drum downward FF Velocities at the point of contact b F F F where F and F and external forces through support Fnet 0 External torque F x 3R anticlockwise F c Let w and w be final angular velocities anticlockwise and clockwise respectively Finally there will be no friction

Two solid conductors are made up of same material have same length and same resistance One of them has a circular cross section of area 4 and the other one has a square cross section of area 4 The ratio 4 4 is 1 1 3 2 2 0 8 4 1 5

A road curve is banked so that there is no side thrust the passengers in a car which negotiate the curve 72 km hr speed Find the angle of banking for a cir lar curve making a 90 turn in a distance of 157 22 14 along the road

Q 61 SINGLE CHOICE Which of the following graph corresponds to a population of 2000 individuals with 800 births and 1200 deaths over a given period of time A Population Correct Answer Population

The energy levels of a certain atom for first second E and third levels are E 4 and 2E respectively 3 A photon of wavelength is emitted for a transition 3 1 What will be the wavelength of emission for transition 2 1 1 3 32 2 3A 1 42

The focal lengths of the objective and eye piece of a compound respectively microscope are 2 cm and 3 cm The distance between the objective and eye piece is 15 cm The fina image formed is at infinity The distances in cm of object and image from objective are 1 2 4 and 12 2 2 4 and 15 3 2 4 and 3 0 4 2 3 and 12 OPTICAL INSTRUMENTS

B A barometer is constructed using a liquid density 760 kg m What would be the height of the liquid column when a mercury barometer reads 76 cm density of mercury 13600 kg m 1 13 6 m 2 136 m 3 0 76 m 4 1 36 m

Find the current flowing through R in the circuit below assuming the diodes to be ideal R V 10V O Zero O 0 5 mA O 1 MA O 2 MA R ww R R 10KQ R 5KQ R 5K0