Physics Questions

1 Two point charges 4e and e are at a distance d apart What should be the sign of a third point charge q to be placed between them so that a q is in equilibrium h the entire system is in equilibrium

Consider a syringe of diameter 10 mm and a needle of diameter 1 mm attached to it In order to administer the Corona virus vaccine a nurse is pushing the piston in the syringe keeping it horizontal If the vaccine is having a velocity of 10 mm s inside the syringe then find the force applied by the nurse on the piston Take density of vaccine as 1 gm cm and assume that the needle releases the vaccine to atmospheric pressure O 0 039N O 1 2N O 0 156N O 0 078N

A number of projectiles each with same speed u are fired at different angles lying between 0 and 90 as shown Neglecting air resistance and assuming g to be constant then the equation of the envelop E of the parabolic trajectories as shown in figure is Y C E 92 O 27

28 A diatomic molecule can be modelled as two rigid balls connected with spring such that the balls can vibrate with respect to centre of mass of the system spring balls Consider a diatomic gas made of such diatomic molecule If the gas performs 20 Joule of work under isobaric condition then heat given to the gas is J

Three particles P Q and R are situated at corners of an equilateral triangle of side length d At t 0 they started to move such that P is moving towards Q Q is moving towards R and R is moving towards P at every instant After how much time in second will they meet each other a DU P 62d 3u u R 2d 3 u c d d 3 u

There is a cubical cavity inside a conduct ing sphere of radius R A positive point charge Q is placed at the centre of the cube and another positive charge q is placed at a distance R from the centre of the sphere The sphere is earthed A Charge induced on the inner surface of cavity is B C B R D Q uniformly distributed Q non uniformly distributed q Q q non uniformly distributed None of these

Answer the following by appropriately matching the lists based on the informatio given in the paragraph block of mass 10 kg is at rest on rough inclined of inclination 37 with help of a constant orce F Force F have magnitude 20 N At t 0 another force F start acting on block Magnitude of force F changes with time as F 10t N Both forces F and F are parallel to inclined and are acting up the inclined Friction force acting on block is f Match the list I and List II III t 10 sec IV t 15 sec 10kg 37 Coefficient of friction between block and inclined is 0 5 List I f I I t 4 sec II t 7 sec A IS II T III Q IV R P II R III S IV T F 20N F 10t P Q List II II f 0 f 30 N R f 40 N S f 60 N T f 80 N U f 100 N B I P II Q III R IV R D I S II Q III R IV P

Q 18 A wire carrying current carrying current i has the configuration shown in figure For the magnetic field to be zero at the centre of the circle 0 must be R De 1 1 radian 3 radian 2 2 radian 4 2 radian

Q Katrina and Kareena were crossing a river which is flowing towards right at constant speed 5m min travelling in two different boats having same speed in still water They have taken photographs of the river banks at t 0 t T t 2T times Bo Co are two trees on other bank of river Distance shown in diagram are in m Photograph taken by Katrina B Bo t 0 15 3 15 3 13 10 30 Photograph taken by Kareena 1 0 0 B t T c 10 3 Bol t 2TC 5 5 19 5 3 2T T 1 min Mark the correct option A Velocity of boat in still water will be 10 m min B Velocity of boat in still water will be 10 3 m min C Velocity of boat in still water will be 10 3 m min D Valoite of heat in still ill be 5 12 malmin

The time period of oscillation of the system 11m shown in the figure is given by T nk Find the value of n T ABRI 2k 2 reeeee eeeee m eeeee k Au m 11m nk 2

PQ and RS are long parallel conductors separated by certain distance M is the midpoint between them The magnitude of net magnetic field at M is 2B Now the current 1 A is switched off Then the magnitude of the field at M now becomes P R O 2B 3 O 4B 3 O 2B OB 2A M S 1A

In an ideal Atwood machine having only two blocks on either side of pulley the sum of two masses is constant If the string can sustain a tension equal to 24 of the weight of the sum of the two masses then the least 50 acceleration of the masses would be in ms 2 g 10ms 2 02 O 5 4

In the diagram shown below wavefront and AO and BP the corresponding two rays The condition of 0 for constructive interference at P between the ray BP and reflected ray OP is Nd then N is cose 02 Q C A R d X P

2 21 23 Ne decays to 23Na by negative beta emission Mass of 23 Ne is 22 994465 amu mass of 23Na is 22 989768 amu The maximum kinetic energy of emitted electrons neglecting the kinetic energy of recoiling product nucleus is MeV

Q No 2 Luvit your un upevne VIL VI RIVAL THAN THE ECO super omnes For each question choose the option s corresponding to all the correct answer s Answer to each question will be evaluated according to the following marking scheme Full Marks 4 If only all the correct option s is are chosen Partial Marks 3 2 Partial Marks Partial Marks Zero Marks 1 0 Negative Marks 2 For Example If first third and fourth are the ONLY three correct options for a question with second option being an incorrect option selecting only all the three correct options will result in 4 marks Selecting only two of the three correct options e g the first and fourth options without selecting any incorrect option second option in this case will result in 2 marks Selecting only one of the three correct options either first or third or fourth option without selecting any incorrect option second option in this case will result in 1 marks Selecting any incorrect option s second option in this case with or without selection of any correct option s will result in 2 marks D If all the four options are correct but ONLY three options are chosen If three or more options are correct but ONLY two options are chosen and both of which are correct If two or more options are correct but ONLY one option is chosen and it is a correct option If none of the options is chosen i e the question is unanswered In all other cases A ring of mass 2m and radius R is set into pure rolling on horizontal rough surface in a uniform magnetic field of strength B as shown in the figure A point charge q of negligible mass is attached to rolling ring Friction is sufficient so that it does not slip at any point of its motion 8 is measured in clockwise from positive y axis x x x x2mx x x x x x x x x 9x x x x x x X X X X X XXXXXXX X X X X X X X X X X XX X X X X X X X X X X X X www XXX X X X X X X X X X 0 X X Ring will continue to move with constant kinetic energy is 2mv The torque of friction about center of ring is BqvRcose Dino View In English V XX X

52 A point object P is placed at 0 0 and a plane mirror M is placed inclined 30 with the x axis then the position coordinates of image is 2 3 15 1 0 30 3 4 mmm 3 3

The speed time graph of a car is given here Using the data in the graph calculate the total distance covered by the car a 1250 m 30 b 875 m c 1500 m d 870 m 25 20 speed in m s 10 5 15 0 A B 10 20 time in s C D E 30 40 G H 50 5

59 Two mirrors labelled L for left mirror and L for right mirror in the figure are parallel to each other and 3 0 m apart A person standing 1 0 m from the right mirror L looks into this mirror and sees a series of images The second nearest image seen in the right mirror is situated at a distance 1 2 0 m from the person 3 6 0 m from the person W 2m 1m 2 4 0 m from the person 4 8 0 m from the person

1 On a capacitor of capacitance Co following steps are performed in the order as given in column I A Capacitor is charged by connecting it across a battery of EMF V B Dielectric of dielectric constant k and thickness d is inserted C Capacitor is disconnected from battery D Separation between plates is doubled Column I Steps performed ROMAYE A a d c B d a c b C b a c d D a b d c Column II Final value of Quantity Symbols have usual meaning P Q Q Q R C S V C V 2 kC V k 1 kCo k 1 V k 1 2k ATHE

A wooden stick of length L radius R and density P has a small metal piece of mass m of negligible volume attached to its one end The minimum value for the mass m in terms of given parameters that would make the stick float vertically in stable equilibrium in a liquid of density KR 2 P 1 Find the value of K if the rod is not submerged completely in the liquid O is T LP O O O 1 2 4

Two particles are projected from position A and B seperated by a distance of 80 m on horizontal ground If both the particles collides in mid air Select the correct statement Both particles are projected simultaneously A They will collide if angle of projection for A is 37 B Particles will collide somewhere between the two points A and B for any value of 0 C Particles will collide at t 1 sec after projection D They will collide if angle of projection for A is 53 40 2 m s 50m s

A conducting rod AB moves parallel to X axis in a uniform magnetic field pointing in the positive Z direction The end A of the rod gets 1 Positively charged 2 Negatively charged 3 Neutral 4 First positively charged and then negatively charged X

Variable F F2 F3 0 d d2 F Values for the figure are given in the following table Note the figure may not be to scale Value 200 N d d3 590 N 310 N 25 degrees 2m 3 m 4m 0 N m F2 Which direction is MR o rotating F3 a Using Varignon s Theorem determine the magnitude of the resultant moment MR o produced by the forces about point 0 Round your final answers to 3 significant digits figures MR O

A point object is placed at a point P infront of a plane mirror MN then the position coordinate of the image will be Y N 4 3 II M 4 2 P 2 0 6 0 O 2 3 O 2 0 O 4 0 X Marks

Two wires A and B are having lengths of 40 cm and 30 cm respectively Both of them are bent in the form of a circle such that current in is passed through A and is through B To have the same magnetic induction at the centre the ratio of i i is 04 3 02 3 03 2 03 4

A circular coil of radius 10 cm has a concentric and coplanar circular coil of radius 0 01 cm The approximate value of the coefficient of mutual inductance of the coils wil be 2x 10 13 H 4 x 10 6 H 8 x 10 11 H 6 x 10 8 H

a b 4r 2r Y 2 40 A circular coil of radius R carries an electric current The magnetic field due to the coil at a point on the axis at a distance x from the centre of coil is th of the magnetic field at the centre of coil 8 Value of x is a R b 2R c 2R d 3R

diameter 1 mm attached to it In order to administer the Corona virus vaccine a nurse is pushing the piston in the syringe keeping it horizontal If the vaccine is having a velocity of 10 mm s inside the syringe then find the force applied by the nurse on the piston Take density of vaccine as 1 gm cm and assume that the needle releases the vaccine to atmospheric pressure O O 0 039N 0 156N

5 refractive index RI to another 3 medium at an angle 30 The angle of 5 refraction for other medium is sin 6 then the increase in angle of incidence is such that the ray of light reflected back 1

A cell of e m f 2 V and negligible internal resistance is connected in series with a potentiometer wire of length 100 cm The e m f of the Leclanche cell is found to balance on 75 cm of the potentiometer wire The e m f of the cell is A 3 5 V e 1 5 V B 2 5 V D 0 5 V

A 6 8 kg block slides down a rough incline with some support from a rope the rope pulls vertically upwards like in the picture below The angle of the incline is 34 degrees and the coefficient of friction between the block and the incline is 0 13 You pull on the rope with a force of 52 N This is NOT a large enough force to lift the block upwards off the incline What is the acceleration of the block in m s

Which of the following statements is correct A A plane mirror can produce a magnified image B Displacement method experiment can be performed with a diverging lens Octwo mirrors inclined at some angle will form infinite number of images of any object placed between them OD Lenses with higher curvature of the refracting surfaces have higher converging or diverging power depending on the nature of th

Aforce F x 3 00x iz acts on a particle as the particle moves along anxaxis within newtons x in meters and ca constant Atx 0 m the particle s kinetic energy is 20 0 J at x 3 00 m it is 11 0 J Find c Number Units

A body of radius R and radius of gyration K about axis of rotation is rolling without slipping The fraction of its kinetic energy is in form of rotational kinetic energy is 1 R2 K R K R 1 X R

Two 500 g blocks of wood are 2 0 apa frictionless table A 10 g bullet is fired at 430 m s toward the blocks It passes all the way through the first block then embeds itself in the second block The speed of the first block immediately afterward is 5 2 m s Part A What is the speed of the second block after the bullet stops Express your answer with the appropriate units

15 C 8 m D 6 m 3 grooves AB AC and AD are made in a circular disk lying in a vertical plane 3 particles B C and D constrained to move along path AB AC and AD respectively are released from point A Particle B reaches point B in time te particle C reaches point C in time t and particle D reaches at point D in time to Then which of the following is incorrect s A te tc to te te to B te t to D to te tc B 25

A small spher density p falls from rest vertically from a height h into a liquid of density 3 P The period of oscillation is O O O 3 A 2 2h 9 2h 9 2h 9 3h

13 Three long straight wires A B and C are carrying current as shown in figure Resultant force on B is directed A 1AV B 2AV C 2A d d 1 Towards A 2 Towards C 3 Perpendicular to the plane of paper and inward Perpendicular to the plane of paper and outward

All Questions are compulsory SECTION A Read the following passage carefully and answer the questions given below 10 Surrounded by the Vindhya ranges Bhimbetka caves lie 46 kms South of Bhopal Over 600 rock shelters belonging to the Niolithic age were discovered in the midst of a dense forest Here paintings in our 500 caves depict the life of the pre historic cave dwellers making Bhimbetka an archeological treasure Paintings are mainly in red and white with the occasional use of green and yellow The scenes usually depict hunting dancing music horse and elephant riders animals fighting honey collection decoration of bodies maskes and household scenes Animals such a bisons tigers lions bears elephants antelopes dogs lizards crocodiles etc have depicted in these caves Popular religious and other symbols also occur frequently The Superimposition of paintings shows that the some rock surface was used by different people at different times Questions 1 How for is Bhimbetika from Bhopal 2 Whose life is depticted in the painting 3 What are the colours used in these paintings I see in these paintings Q 1

concave mirror is producing a virtual image of the object Which of the following statement is incorrect A The linear magnification is always greater than one Except at the pole B The linear magnification is always less than one c The magnification tends to one as the object move nearer to the pole of the mirror D The distance of the object from the pole of the mirror is less than the focal length of mirror

Select the correct option about the friction between the two bodies 1 Static friction is always greater than the kinetic friction Limiting friction is always greater than the kinetic friction 3 Limiting friction is not always greater than the kinetic friction 4 The direction of friction is always opposite to motion

39 An ideal heat engine operates in a Carnot cycle between 227 C and 127 C It absorbs 6 kJ of heat at the higher temperature The amount of heat converted into work is a 1 2 kJ c 3 5 kJ b 1 6 kJ d 4 8 kJ CBSE PMT 3

d 2 3 4 69 For what value of R in the circuit as shown in figure current passing throu zero B www 202 9 V a 10 30 ww LL F 402 6 V 3 V R E resistance will be YSICSKOTA

A rock is thrown upward from a bridge that is 38 feet above a road The rock reaches its maximum height above the road 0 51 seconds after it is thrown and contacts the road 3 15 seconds after it was thrown Write a function f that determines the rock s height above the road in feet in terms of the number of seconds t since the rock was thrown

th a a 6 V c 3 V c 3 4 NEET 16 I 73 The potential different VA VB between the points A and B in the given figure is VA O A b 5 4 d 3 2 I 2A 222 3 V wwwwww b 9V d 3V 192 VB B is NEET 16 II

The number of free electrons per 10 mm of an ordinary wire copper wire is about 2 1021 If the average drift speed of the electrons is 0 25 mm sec then the electric current flowing through the wire is O 80 A O 0 08 A O 0 8 A O 8A Marks 4 1

1 10 km h at 0 Column I 1 2 3 2 5 3 km h at 60 3 10 3 km h at 30 4 5 3 km h at 30 Column II P 53 If swimmer can swim at 5m sec in still water and if velocity of water flow is 4m sec then angle between direction of swimming and direction of river flow to minimize drift If swimmer can swim at 5m sec in still water and velocity of flow is 3m sec then angle between direction of velocity of swimmer with respect to river and the direction of river flow if swimmer crosses the river in minimum time If swimmer can swim at 4 m sec and velocity of flow is 3m sec then angle of resultant velocity w r t ground with the direction of river flow if swimmer heads perpendicular to flow of river Angle between direction of fluttering of flag and north if wind blows towards south west direction with a velocity 3 2 m sec Man moves with a velocity 7m sec along west holding flag in his hand Q 127 R 143 S 90

A light wave is incident normally on a glass slab of refractive index 1 5 If 4 of light gets reflected and the amplitude of the electric field of the incident light is 30 V m then the amplitude of the electric field for the wave propogating in the glass medium will be 1 30 V m 3 24 V m 10 V m 2 4 6 V m

A block of mass M is held against a rough vertical wall by pressing it with a finger If the coefficient of friction between the block and the wall is and acceleration due to gravity is g the minimum force required to be applied by the finger to hold the block against wall is 1 3 Mg Mg M 1 2 Mg 4 1 Mg

horizontal position as shown For what value of angle between string and vertical during its motion the total acceleration is directed horizontally O O O 90 0 90 1 COS Sin 1 3 1