Physics Questions

2 18 The dielectric to be used in a parallel plate capacitor has a dielectric constant of 3 6 and a dielectric strength of 1 60 x 107V m The capacitor is to have a capacitance of 1 25 10 F and must be able to withstand a maximum potential difference of 5500V What is the minimum area the plates of the capacitor may have Ans 0 0135m

The resistance of the wire in platinum resistance thermometer at ice point is 3 2 and at steam point is 9 Q2 When the thermometer is inserted in an unknown hot bath its resistance is found to be 12 Q The temperature of the hot bath is A 100 C B 50 C C 75 C D 150 C

Q14 A blue ball of mass 5kg is tied to a string of length 2m and swung in a loop with a velocity of 1 m s A red ball of mass 10 kg is tied to a string of the same material and length and swung with the same velocity in a loop Then O A The centripetal acceleration of red ball is double that of blue ball O B The centripetal acceleration of red ball is half of that of blue ball O C The centripetal acceleration of red ball is 4 times as that of the red ball O D The centripetal acceleration is the same for both balls

A parallel plate capacitor is made of two plates of length width and separated by distance d A dielectric slab dielectric constant K that fits exactly between the plates is held near the edge of the plates It is pulled into the capacitor by a force au F where U is the energy of the capacitor when dielectric is inside the capacitor up to distance x see figure If the charge on the capacitor is Q then the force on the dielectric when it is near the edge is Q d A B 201 ED C K K 1 2d1 p D Q d 201 p Q w K 2d1 n K 1 1

Question given below has answer in Numerical Value You need to enter the Numeric Value using your keypad For CORRECT Value there is NO NEGATIVE marking No marks will be deducted if you leave question unattempted 1 A particle moves along the positive branch of the curve y 4 2x where x x and y are 2 measured in metre and t in second At t 3s the velocity of the particle in m s is

If the magnetic field of earth at any point on the magnetic equator is 0 4 x 10 T then the value o magnetic field at the magnetic pole of the earth i approximately 10 4 104 T 2 0 2 x 10 T 3 0 8 x 10 4 T 4 0 3 x 10 T St unit of intensity of magnetisation is

A particle of mass 2 kg travels along a straight line with velocity v a x where a is a constant The work done by net force during the displacement of particle from x 0 to x 4 m is 1 a 2 2a 3 4a 4 12 0

2 P and Q 3 P and Q 4 Q and Q Assume that each iron atom has a permanent magnetic moment equal to 4 Bohr magnetons 1 Bohr magneton 9 27 x 10 24 Am The density of atoms in iron is 8 52 x 1028 atoms m The maximum intensity of magnetization in a long cylinder of iron is 1 0 58 x 106 A m 2 2 58 x 106 A m 3 1 16 x 106 A m 4 3 16 x 106 A m wer 8 Pusa Road New Delhi 110005 Ph 011 47623456

A cylinder of 0 9 m in volume contains air at 0 C and 39 24 N cm2 absolute pressure The air compressed to 0 45 m Find i the pressure inside the cylinder assuming isothermal proces ii pressure and temperature assuming adiabatic process Take k 1 4 for air Ans i 78 48 N cm ii 103 5 N m 140 C

option without selecting any incorrect option second option in this case will result in t marks A 1 kg block is kept on L shaped block of mass 2 kg which is kept on horizontal surface as shown A force F 2N is applied on the massless string which is connected to 1 kg block Coefficient of friction between the blocks 0 1 There is no friction between 2 kg block and ground Pulley is massless and frictionless Choose the correct options s Acceleration of 1 kg block is 1 m s Acceleration of 2 kg block is 2 m s Acceleration of 2 kg block with respect to 1 kg block is 2 5 m s Net force on 2 kg block is 4 N 2kg F 2N 1kg Save

9 At what depth from earth surface the acceleration due to gravity is changed by 5 geat at de fondai Teus 4 yaralu aku 5 Rafa Gr m 2 640 km 3 320 km 1 64 km 4 32 km 0 A negative charge is coming towards the observer The direction of the magnetic field produced by it will be as seen by observer S304 giacha fa I al 3ch RI v G T

28 The mean lives of a radioactive substances are 2000 years and 400 years for a and emission respectively What will be the time in years after which 5 6th of the given sample will decay if it is decaying by both a and B emission together In 6 1 79 1 297 2 397 3 597

of mass 100 g is dropped from a height of 1 m It loses 10 of its energy every time when it bounces off the floor After 3 bounces it car reach the half way to maximum height its kinetic energy upto two decimal points would be take g 10 m s 3 20 1 0 35 J 0 36 J 0 70 J 40 73 J 2 3 9 To D 1 0 09 81 1 210 0 TO 03 0 81 0 72 8 10 72

A magnet is oscillating with time period T in a vertical plane If angle of dip at that place is 60 and the magnet is restricted to oscillate in horizontal plane then the time period oscillations will be

Consider the circuit in the a What current flows from the battery b What is the potential difference between points A and 50 0 2 A ww 20 0 22 20 0 52 40 0 2 wwww ww wwww 70 0 2 20 0 52 120 V For the toolbar press ALT F10 PC or ALT FN F10 Mac Arial B 14px

Sir Ma am please explain just the last option how force is conservative here I had posted this as my query and exce pt for the required last option all other options are explain ed Sir Ma am how to say if the force is conservative or not ie the last option Aug 15 2021 4 20 23 PM Answered A particle of mass m is initially at rest at the origin It is subjected to a force and starts moving along the x axis Its kinetic energy K changes with time as dk dt rt where is a positive constant of appropriate dimensions Which of the following statements is are true The force applied on the particle is constant The speed of the particle is proportional to time The distance of the particle from the origin increases linearly with time The force is conservative

A body is moving in a low circu about a planet of mass M and ra The radius of the orbit can be taken itself Then the ratio of the speec body in the orbit to the escape from the planet is A 2 C 2 B 1 D 5

Inside the plates of a parallel plate capacitor of area A distance d a dielectric slab of dielectric constant K is inserted battery of emf V is connected to the plates of the capacitor After a long time the battery is removed If the dielectric slab is now taken out of the capacitor calculate the work required to remove the slab A EAV 2Kd B 1 K AV 2Kd C K 1 AV 2d D K K 1 AV 2d

For a transparent medium relative permeability and permittivity u and e are 1 0 and 1 44 respectively The velocity of light in this medium would be NEET 2019 Odisha 2 2 5 108 m s 4 2 08 108 m s 1 4 32 108 m s 3 3 x 108 m s o

Question given below has four answer options out of which ONE OR MORE is are correct For all CORRECT options selected you will be awarded 4 Marks ar each correct option selected provided NO INCORRECT option is selected For WRONG answer there is a NEGATIVE marking of 2 Marks No marks will be dec unattempted A stone is thrown from a point at a distance a from a wall of height b If it just clears the wall the maximum height reached by the stone if the angle of projection is a is A B C D a sec a 4 a seca b a tan a 4 atana b a tana 4 a bcota tan a

Consider a circuit as shown in figure Then choose correct statement s 20 30 wwwww 50 10V 402 60 If 40 resistance is shorted resistance less wire connected in parallel to it the current through battery will increase If 402 resistor is shorted the current through 50 resistance will decrease O If instead of 40 50 resistor is shorted current through battery will decrease If instead of 40 30 resistor is shorted current through battery will decrease

slipping C is the centre of disc and m 3kg k 10 N m The time period of small oscillations is L C sooooor 111 O 0 6 k 100000

1 If both Assertion Reason are true and the reason is the correct explanation of the assertion then mark 1 2 If both Assertion Reason are true but the reason is not the correct explanation of the assertion then mark 2 3 If Assertion is true statement but Reason is false then mark 3 4 If both Assertion and Reason are false statements then mark 4 A The permeability of a ferromagnetic material is independent of the magnetic field R Permeability of a material is a constant Quantity 31 32

A train moving at uniform 90 km h is approaching a flag station whose platform is 500 m long Station master is standing a the centre of the platform Train start blowing whistle when engine is 1 km awa from near end of the platform and continue blowing whistle till engine crosses of th platform without stopping If the speed c the sound is assumed to be 300 m s the the duration for which station master Hea the whistle is 1 55 80 sec 56 67 sec 60 00 sec 60 30 sec 3 4 25m 5 Vs 2300m

30 Figure shows the velocity versus time 30 50 fanf graph for a block of mass 50 g sliding on a rough floor The average rate at which energy dissipates in s due to the force of friction is AKCE 160 J in 8 sec 160 640g 205 in 1 sec 1 5 0 J s 2 10 0 J s 320 0 J s 4 40 0 J s 13 15 SAT ENG HIN v 4 m s 80 88 60 40 20 0 s time S 5 0 J s 10 0 J s 20 0 J s 4 40 0 J s 8 10 1 2 3

A beam having photon of energy 480 k eV is incident on a foil of aluminum If the photon is scattered at 45 then calculate the energy of the recoil electron a 2 56 10 4 J b 1 65 10 14 J c 3 28x10 4 J d 4 12 10 4 J

In a space electric field is acting parallel to x axis wherever it is present Variation of electric potential v s position x as shown Choose the correct statement s n 5 volt 2m 4m 5m 10 volt A if an electron is released from x 5 then it can reach to x 0 B if an electron is released from x 0 then it can reach to x 5 C if a proton is released from x 5 then it can reach to x 0 D if a proton is released from x 0 then it can reach to x 5

20 g of ice at 20 C is dropped into a calorimeter containing 20 g water at 10 C The specific heat of water is twice that of ice The amount of water contained in the calorimeter when equilibrium is reached is 1 20 g 2 10 g

Torque of Viscous Forces on a Disc Figure shows a disc D of diameter d connected to an axle placed on a fixed horizontal surface There exist a thin layer of a lubricant of viscosity n between disc and ground of thickness t Find the external torque required to rotate the disc at a uniform angular velocity 0 t D 4

90 Design a counter which counts from 0 to 15 using positive edge clock pulse Draw the sequential circuit using CIRCUIT VERSE tool How we can say that J K flip flop is a universal flip flop Explain

In the circuit shown the potential energy stored in the 20 F capacitor is ImJ Find the total potential energy stored in the two unknown capacitors A 0 5 mJ B ImJ C 2 5mJ D 3 5 mJ 20 F 5 F 30V

The VC shown in the diagram has zero error in it as you can see It is given that 9 msd 10 vsd The observed reading of the length of a rod measured by this VC comes out to be 5 4 mm If the vernier had been error free then reading of main scale would be and the coinciding division of vernier scale would be zero of vernier scale a 6 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 b 6 3 c 6 4 d 7 3

The capacitors C and C3 in the circuit shown carry 5uC and 15 C charge respectively If the capacitors C and C store equal potential energy find the emf of the battery A 6 67 V B 7 5 V C 8 33 V D 10 V C 2 F

The possible value of magnetic susceptibility of a diamagnetic material can be 1 2 45 3 0 5 2 0 75 4 1 67 tion factor of tangent galvanomete

In a parallel plate capacitor the region between the plates is filled by a dielectric slab The capacitor is connected to a cell and the slab is taken out While removing the dielectric A Some charge is drawn from the cell B Some charge is returned to the cell C The electric field between the plates is increased D The electric field between the plates remains unchanged

Each of the wo identical magnets when suspended alone makes 30 oscillation per minute at a place The number of oscillation per minute if they are fixed at right angles and allowed to oscillate in the same field will be approximately 1 25 oscillation minute 2 30 oscillation minute 3 60 oscillation minute 1 15 oscillation minute

A negative charge is coming towards the observer The direction of the magnetic field produced by it wil be as seen by observer feel GRI GI Y 1 Clockwise 3 In the direction of motion of charge 1 fa 3 fam R34 2 Anti clockwise 4 In the direction opposite to the motion charge 2 4 ffaria farm

6 Radius of a circular loop placed in a perpendicular uniform magnetic field is increasing at a constant rate of ro ms If at any instant radius of the loop is r then emf induced in the loop at that instant will be Good Hy Lacter 7 v gu q4 frvell field Gromsi aa fb GI I TR 14 2 2B r 1 2Bmo 3 Baror 4 2B ror

20 A particle moves along a circle of radius m with constant tangential acceleration If the velocity o T the particle is 80 m s at the end of the second revolution after motion has begin the tangential acceleration is 45 44 45447 2xi tela aru ya ya faus fava 20 m qu U qu Ia ada and di aft 340 80 m s zus trata ca 1 40 ms 2 640 ms 3 160 ms 4 40 ms

7 Amplitude of electric field in an electromagnetic wave of intensity 1 475 W m is nearly 1 49 67 N C 2 33 33 N C 3 66 66 N C 4 53 8 N C shown in the fiqure masses

Two blocks of mass 2 kg and 3kg having coefficient of static friction 0 3 and 0 4 respectively are joined by an ideal spring of constant 100 N m and kept on level ground What can be a possible extension in the spring so that both the blocks are in equilibrium Take g 10 m s 03 cm 6 cm 9 cm 15 cm

After the switch shown in figure A is closed there is current i through resistance R Figure B indicates current variation curves a b c and d for four sets of values of R and capacitanc A Ro and Co B 2Ro and Co C Ro and 2Co D 2Ro and 2Co Which set goes with which curve R E Figure A C HH a A b C c B d D a B b D c A d C a D b B c A d C a C b A c B d D Figure B

Here a is the angle formed by the helical line of groove with the horizontal plane A component of the acceleration of the body is responsible for change in direction other for the change in speed i e centripetal acceleration tangential acceleration The tangential acceleration have two components one along the circle one in vertical direction The value of tangential acceleration at can be found by mentally developing the surface of the cylinder with the helical groove into a plane In this case the groove will become an inclined plane nh 2 Rn Distance travelled by the object when it completes one revolution along the groove is

69 The triangular plate described in the last question has angle A 0 Now find its moment of inertia about an axis through A perpendicular to the plane of the plate same A 0 a a B

A ball falls vertically onto a floor with momentum p and then bounces repeatedly The coefficient of restitution is e The total momentum imparted by the ball to the floor is S p 1 e 3 p 1 e 2 1 e 2 p 4 1 e 1 e 1 e 1 e

An elliptical smooth wire frame carries a bead of mass m and is moved along X axis in a vertical plane At equilibrium the co ordinates of the bead with respect to origin O may Y I 1 8 1 6 m O 1 8 1 6 m O 1 6 1 8 m 1 6 1 8 m m 2m 3m a 5 m s X

In Davisson and Germer experiment for waw nature of electron if voltage between filament an that of anode is increased by five percent th new wavelength corresponding to electron a wave becomes 1 5 times 3 20 21 times 2 4 times 21 22 times

3 Energy of atom 4 Speed Radius 25 Consider a hydrogen like atom in Bohr s model It is given that difference between n 1 th Bohr s radius and nth Bohr s radius is equal to n 1 th Bohr s radius then the energy of nth state in eV is Z atomic number 1 0 85 2 2 1 5 Z 3 13 6 2

ns ol C Find dimensional formula of if where C capacity V Voltage V 3 M LT A 4 M L T A 1 M L T A 2 M L T A 1 C M L T A V M LT A M L T A 1

42 Consider the following two statements a Capacitances are called inertia of electrical circuits b Keeping only radius of cross section of solenoid constant if number of turns of a solenoid are increased then its self inductance always increases The correct statement s is are K 1 Only a 3 3 Both a and b Only b 4 Neither a nor b topon of the following circu