Physics Questions

A nucleus of mass number A initially at rest emits an alpha particle The de Broglie wavelength of the emitted alpha particle is 2 Immediately after the emission the de Broglie wavelength of the nucleus is

A circular loop has a radius 20 cm is placed in a uniform magnetic field B 2T in the XY plane as shown The loop carries current i 1A The magnitude of torque acting on the loop is 1 0 25 N m 1 5 2 N m 3 2 5 N m 4 052 N m 450 B X

FH Of A uniform rod of length is pivoted at one of its ends or a vertical shaft of negligible radius When the shaft rotates at angular speed to the rod makes an angle 0 with it see figure To find e equate the rate of change of angula momentum direction going into the paper ml 12 o sin 0 cos about the centre of mass CM to the torque provided by the horizontal and vertical forces F and F about the CM The value of 0 is then such that 1 cos 0 2g 31w 3 cos 0 10 2 cos 0 8 21w 4 cos 3g 1

Two equal point like positive charges A and B are fixed on the y axis equidistant from the origin What can you say for the net electrostatic force on a small electrically neutral conducting rod placed on the x axis as shown in the figure A B C

each of resistance R A battery of negligible internal resistance is connected across the opposite corners A and C of the top face of the cube A current I enters the corner A and leaves the corner C The current passing through the resistor BF is B A zero B C D A B 9 O 3 5R 6 3R 4 E 5R 12 3R www www ww www The effective resistance between the points A and C in the above circuit is www ww H 10 mu ww

Two particles are projected in vertical x y plane from point P and Q as shown in figure If they perform motion under gravity then value of u so op 3 that collision take place during motion oq 4 20 m s 20 m s 53 T 37 2 30 m s

Activity No 4 Speed in angles What you need calculator pen and paper What to do Read each item carefully then answer the questions that follow Show your solutions 1 An object travels a distance of 35 ft in 2 7 seconds as it moves along a circle of radius 2 ft Find its linear and angular speed over that time period 2 An object moves at a constant linear speed of 10 m sec around a circle of radius 4 m How large of a central angle does it sweep out in 3 1 seconds with an outer radius of r1 5 cm 71 5 cm

Two identical charged particles moving with same speed enter a region of uniform magnetic field If one of these enters normal to field direction and the other enters along a direction at 30 with the field what would be the ratio of their angular frequencies 0 tonoid of 4000 If the

A rectangular loop of sides 25 cm and 10 cm carrying a current of 15 A is placed with its longer side parallel to a long straight conductor 2 cm apart carrying a current of 25 A What is the net force on loop

anal area A 100 C and ductivity of stance from the middle ached Variation of density corresponding variation in its volume is as shown questions Temp C 1 Both graphs have been correctly plotted 2 Both graphs have been incorrectly plotted 3 Only variation of density is plotted correctly 4 Only variation of volume is plotted correctly Space for Rough Work T C

If the mean free path of a gas is at one atmospheric pressure then its value at 5 atmospheric pressure will be temperature is assumed to be constant 1 X 3 A 2 5 5 4

In the given circuit diagram switch was connected to position 1 for long time At t 0 switch is shifted from position 1 to position 2 Find the final charge on capacitor 2C C V C 2 Question Type Single Correct Type 20

1 0 C 3 40 C 2 20 C 4 100 C 42 A conducting rod of uniform cross sectional area and length 1 m is kept at temperature 100 weste 1 More than 50 C 2 Less than 50 C 3 Equal to 50 C 4 Indeterminate and 45 0 C maintained at its ends Thermal conductivity of material of rod increases linearly with distance from the hotter end Temperature of rod in the middle will be after steady state condition is reached and quest

In the circuit shown if a conducting wire is connected between points B and D t in this wire will Z th V 462 in 312 a flow from D to B c flow from B to D 1 3 VA VB SA VA 2VB V C VB Vc 4 VA V VD Vc 1 3 FS VA VCD VI b be zero d flow in the direction which will be decided by the value of V developed by changing magnetic flux

1 A car travels with a speed of 20 kmph for one half the distance and other half at 30 kmph If its acceleration is uniform its average speed is B 25 kmph 1 A 24 kmph C 10 kmph D 12 kmph 2 The motion of a particle is represented by the equation s s 4t 8t 5t 4 Its m s acceleration at the end of 2 second is B 40 A 32 A 0 B UNIT TEST NOV 2021 PHYSICS 6 ms 3 The diagram shows the displacement time graph for a particle moving in a straight lir The average velocity for the interval t 0 t 5 is 2 ms C D 2 ms M C 37 4 From the following displacement time graph velocity of the moving body A ms m s B 3 ms C 3 ms 1 D ms 1 X uestion No 1 10 0 10 Mark Correct Time sec N 2 D 35 30 5 If a body is thrown up with the velocity of 15 m s then maximum height attained by the body is g 10 m s A 11 25 m B 16 2 m 6 A projectile fired with initial velocity u at some angle has a range R If the initial velocity be doubled at the same angle of projection then the range will be A 2R B R 2 C R D 4R Displacement meter C 24 5 m Oh 43m 26s D 7 62 m Answer Sheet Answer Next Marks 4 00

A toroid of 4000 turns has outer radius of 26 cm and inner radius of 25 cm If the current in the wire is 10 A calculate the magnetic field of the toroid and also in the inner air space of the toroid The electron in a hydrogen atom circles around the proton with a speed of 2 18 x 10

42 A body of mass m is attached to the lower end of a spring whose upper end is fixed The spring has negligible mass When the mass m is slightly pulled down and released it oscillates with a time period of 3 s When the mass m is increased by 1 kg the time period of oscillations becomes 5 s The value of m in kg is 3 a 4 b 3 c 16 9 9 16 NEET II 2016 d 43 The period of oscillation of a mass M suspended from a spring of negligible mass is T If along with it another mass M is also suspended the period oscillation will now be H T a T b c 2T T d 2T

4 Only i and iii Two particle 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 AIPMT MAINS 2011 C

2 4RTo 4 2RT In 2 1 2RT 3 BRT 35 A body freely floats in a liquid contained in a vessel The whole system fails freely under grav The gram upthrust on the body is 1 Equal to weight of body in air 2 Equal to weight of liquid displaced 3 Equal to weight of the immersed portion 4 Zero

A hollow hemi sphere of mass m and radius r is released from rest in the position shown Knowing that the hemi sphere rolls without sliding Determine the reaction at the horizontal surface at the instant when it has rolled through 90 Question Type Single Correct Type 1 2 7mg 4 5mg 2

The electron in a hydrogen atom circles around the proton with a speed of 2 18 x 10 m s in an orbit of radius 5 3 x 10 m Calculate i the equivalent current and ii the magnetic field produced at the proton A rectangular loop of sides 25 cm and 10 cm carrying a current of 15 A is placed with

A charge q moving along the x axis with a velocity v is subjected to a uniform magnetic field B acting along the z axis as it crosses the origin O Trace its trajectory Does the charge gain kinetic energy as it enters the magnetic field Justify your answer i ii

0 A pendulum is hung from the roof of a sufficiently high building and is moving freely to and fro like a simple harmonic oscillator The acceleration of the bob of the pendulum is 20 m s at a distance of 5 m from the mean position The time period of oscillation is a 2 s b Ts c 2 s d 1 s

1 i ii iv stration 6 32 Two blocks A and B of mass M 3M re connected through a light string One end of the string is con nected to the block B and its other end is connected to a fixed point S as shown in Fig 6 144 Now a force F is applied block B Find the acceleration of block A B M A S B F 3M Segment AL Segment A Segmen A Segmen

A particle starting from the origin 0 0 moves in a straight line in the x y plane It s coordinates at a later time are 3 3 The path of the particle makes an angle of with the x axis A 30 B 45 C 60

a Two plane mirrors are placed at an angle of 60 to each other An object is placed symmetrically between the mirrors Find the number of images formed by the mirror b What should be the angle between two plane mirrors such that the number of images formed is maximum How many images are formed in this case

disintegration of a radioactive sample is R at time t and R at time t2 The half life of the sample is proportional to Only one correct answer A B C t t2 In R R t t In R In R t t D LD

city the nit uld ne 6 87 The density of the core of a planet is p and that of the outer shell is p The radii of the core and that of the planet are R and 2R respectively Gravitational acceleration at the surface of the planet is same as at a depth R Find the p P R Pi P2 Figure 6 114 2R

An air filled parallel plate capacitor has capacitance C When a dielectric medium of dielectric constant k is introduced to fill half of the space between the plates as shown the capacitance becomes 2C The value of k is

41 A spring of force constant k is cut into lengths of ratio 1 2 3 They are connected in series and the new force constant is k Then they are connected in parallel and force constant is k Then k k is a 1 9 b 1 11 c 1 14 d 1 6

The diagram below shows three circuits consisting of circular arcs half or quarter circles of radii r 2r and 3r as indicated and the straight line sections which are radial The three circuits carry the same current Rank them according to the magnitudes of the magnetic fields they produce at the centre of the circles starting with the greatest magnitude 2r 2r i A i ii iii B ii iii i C ii i iii D iii ii i 2r ii 2r r iii 2r

P A particle of mass m is released from rest and follows a parabolic path as shown Assuming that the displacement of the mass from the origin is small which graph correctly depicts the position of the particle as a function of time V x a x t x t b o m x

30 30 1 0 0 m 4 kg 6 Two masses m 4 kg and m 2 kg are released from rest as shown in figure Find Famig my a F X i The distance travelled by centre of mass in 9 s i The speed of centre of mass after 9 s Law of Conservation of Linear Momentum m 2 kg b vat Vem 30 omponent system

3 A rod having moment of inertia I is heated such that its length increases due to thermal expansion The variation of moment of inertia with rise in temperature is best represented by which of the following curve K AT 4 AT AT AT

The work done of vectors force F and distance d separated by angle 6 can be calculated using ans a Cross product d Cannot be calculated b Dot product c Addition of two vectors

4 In the measurement of resistance by Wheatstone meter bridge the known and unknown resistance are interchanged to eliminate O minor error O contact error O observational error 1 F

A cylinder is free to rotate about its axis It angularly accelerate from rest at the rate of TT rad s for a period of 3sec and then it is suddenly reversed in dire without changing the magnitude The angle rotated by the cylinder in time interval 6 to 10 sec is 0 radian If n fill n in the OMR sheet

2 In Sor vibrating length is O O O O poir directly proportional to the tension in the wire directly proportional to the square root of tension in the wire inversely proportional to the tension in the wire inversely proportional to the square root of tension in the wire

3 A particle of mass m hits another particle in rest of mass m obliquely If both the particles after elastica collision moves perpendicular to each other then m m 1 1 is 2 2

Two blocks A and B of same mass M are connected with each other with an ideal string of length 2 passing over an ideal pulley The block A is connected to a light pan C with an ideal string as shown in M figure A particle of mass 2 is dropped on l pan from height 2 as shown If collision between particle and pan is perfectly inelastic acceleration of B just after the collision is M MM A B l

A long cylindrical vessel is half filled with a liquid When the vessel is rotated about its own vertical axis the liquid rises up near the wall If the radius of vessel is 5 cm and its rotational speed is 2 rotations per second then the difference in the heights between the centre and the sides in cm will be A B 2 0 1 2 C 0 1 D 0 4

37 A millivoltmeter of 25 millivolt range is to be converted into an ammeter of 25 ampere range The value in ohm of necessary shunt will be 1 1 3 0 001 AIPMT Prelims 20121 2 0 05 4 0 01

2R 30 A cubical block of side a and density p slides over a fixed inclined plane with constant velocity v There is a thin film of viscous fluid of thickness T between the plane and the block The coefficient of viscosity of the film will be 1 pagt sine pagt tan e pagt cose

1 m Two balls A and B of masses 1 kg each are connected by an inextensible massless string The system is resting on a smooth horizontal surface An impulse of 10 Ns is applied to the ball A at an angle 30 with the line joining two balls in horizontal direction as shown in the figure Assuming that the string remains taut after the impulse if the magnitude of kinetic energy of ball A is 175 k Find the value of K 8 1 kg B30 1 kg A 10 N

3 13 the 54 What should be the value of does not slide over the triangular wedge surfaces are smooth m 4 m m 5 1 m 2 4 3 1 m 5 3 1 2 4 5 5 m 30 M

28 A satellite is launched in the equatorial plane in such a way that it can transmit signals up to 60 latitude on earth Orbital velocity of satellite is 1 gR 3 2gR 2 gR V2 m 4 OR 3 32 Th 1 0 VO 3 Space for Rough Work

A particle executes simple harmonic motion with amplitude A and period T If it is half way between mean position and extreme position then its speed at that point is A B C 3 T 3 TA 2T T

4 Increase in one and decrease in second 23 Consider a thin metallic sheet perpendicular to the plane of the paper moving with speed v in a uniform magnetic field B going into the plane of the paper see fig If charge densities o and o are induced on the left and right surfaces respectively of the sheet then Ignore fringe effects X X X X X X X X X X X X X X X X X X X XXXX X X XXXX X X X X X X X EVB 2 2 a VB a VB EVB 2

Moment of inertia of a rigid body is expressed in units of kg m There are two rods A and B made of same metal Both of them have equal cross sectional are rod A is double in length as compared to rod B What is the ratio of moment of inertia of rod A to that of rod B

Work function of two m surfaces are 2 0 eV and 3 0 eV Both are illuminated by light energy of incident photons greater than 3 eV If graph is plotted between maximum kinetic energy and frequency for both surfaces then slope of the graphs are in the ratio Only one correct answer A 2 3