Basic Physics Questions and Answers

41 There is a set of 4 tuning forks one with lowes frequency vibrating at 552 Hz By using any two forks at a time the beat frequencies heard are 1 2 3 5 7 8 The possible frequencies of othe three forks are 1 553 554 and 560 Hz 2 553 555 and 560 Hz 3 553 556 and 558 Hz 4 551 554 and 560 Hz

a A disk of radius 4 having a uniformly distributed charge 6 C is placed in the X Y plane with its centre at a 2 a 5a 0 0 A rod of length a carrying a uniformly distributed charge 8 C is placed on the x axis from x 4 to x 4 3a 3a respectively Consider a cubical Two point charges 7 C and 3 C are placed at 4 4 surface formed by six surface x a a a 2 y 2 z 2 The electric flux through this cubical surface is a a 1 7 0 and Question Type Single Correct Type 1 2C 0

les a loop in steady state current I The loop is in air Calculate the magnetic flux density vector at a point P located at the fourth vertex of the square a a P

3 1 kPa 4 Zero 38 A gas takes part in thermodynamic process in which it Destion is heated from same initial state to same final as temperature The processes are shown in indicator diagram as 1 2 and 1 3 Then choose the correct option 1 Q Q 2 3 W W 13 2 Q Q 2 4 Au 0

One proton beam enters a magnetic field of 10 T normally Specific charge 10 C kg velocity 10 m s What is the radius of the circle described by it 1 0 1m 2 1m 3 10m

14 If a graph of T versus M is plotted then mass of the given spring from the graph is equal to 1 point O magnitude of negative X intercept Oslope of the graph O 3 x slope of the graph O 3 x magnitude of the negative X intercept

Mobility of electrons in N type Ge is 5000 cm volt sec and conductivity 5 mho cm If effect of holes is negligible then impurity concentration will be 1 6 25 10 5 cm 3 6 10 3 cm 2 9 25 x 10 4 cm 4 9 x 10 3 cm

W ment section tai The acceleration of the block B in the assuming the surfaces and the pulleys P are all smooth and pulleys and strir light is 3F xm then the value of x is P P2 4m B A 11 B 17 C 7

An electron is in a finite square well that is 0 6 eV deep and 2 1 nm wide Calculate the energy of the lowest state that an electron is allowed to occupy in this well Give answer in eV to 3 sf

y iment y A plane is inclined at an angle of 30 A body is projected from the bottom of the inclined plane at an angle of 60 with the ground at a speed of 20 m s Find the range and time of flight 30 20 m s u 60 30 X A B 4 75 S m 3 3 4 80 S 3 m E 3 75 C 4s m 3 80 D 4s m

The extension in a string obeying Hooke s law is y when velocity of wave in it is v If extension is increased to 1 5y then velocity of wave becomes v then 1 v v 3 v 1 5v 2 V 1 22v 4 V 0 75v ange Telegram

What is the meaning of of neutralization 1 poin The heat is given out when 1 mol of O salt is formed from the reaction between acid and alkali O The heat absorbed when acid reacts with a alkali The heat is given out when 1 mol of Owater is formed from the reaction between acid and alkali The heat released when acid reacts

In an experiment a magnet with its magnetic moment along the axis of a circular coil and directed towards the coil is withdrawn away from the coil and parallel to itself The induced current in the coil as seen by the withdrawing magnet is 1 zero 3 anti clockwise 2 clockwise 4 infinity K COA 3

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

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

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

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

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

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

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

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

Define gradient of scalar function and explain it s geometrical significance If 7x y y x find grad at the point 1 3 2 Define divergence of a vector function and explain its physical interpretation by 2 7 1 considering a fluid flow through a rectangular parallelopiped Show that V

17 The oscillation of a body on a smooth horizontal surface is represented by the equation X A cos cot where X displacement at time t frequency of oscillation Which one of the following graphs shows correctly the variation of a with t Here a acceleration at time t T time period M a T H H T b o c o d o T 2014

Q No 28 View In English A long straight wire carrying a current of 1 0 A is placed horizontally in a uniform magnetic field B 10 x 10 5T pointing vertically upward figure The magnitude of the resultant magnetic fiel points P and Q both situated at a distance of 20 cm from the wire in the same horizontal plane are respectively P 1 3 Correct Answer 2 Your Answer 4 BO zero 20 T 20 T zero zero zero 20 T 20 T

An object comprises of a uniform ring of radius R and its uniform chord AB not necessarily made of the same material as shown Which of the following can not be the centre of mass of the object B

26 A piston arrangement pushes a liquid with speed of 2 cm sec The radii of container and its nozzle are 10 cm and 2 mm respectively The velocity of liquid coming out of the nozzle is 1 500 cm s 3 50 m s com r 2 mm 2 500 m s 4 500 mm s 3

A body performing simple harmonic motion has potential energy Pi at displacement Its potential energy is P2 at displacement x The potential energy P at displacement x x is P P A P P P P DP P2 2 P P B C

Let 0 be the angle between vectors A and B Which of the following figures correctly represents the angle 0 1 tot B 0 0 B 2 4 B B A

An asteroid in space initially at rest explodes into two pieces A and B which then move in opposite directions Piece A has less mass than piece B Ignore external forces Identify correct statements Piece A Piece B

O Mohan wears a special kind of a spectacle that produces an upright image on the retina then he will a see everything upside down 14 75e everything upright c initially see everything upside down but regain normal upright vision after a month d initially see everything upright but after a few hours see everything upside down

Choose the CORRECT statement Work energy theorem can not be applied if non conservative forces are doing work O Centre of mass of an object may lie outside the object For all the cases centre of mass is the point where whole mass of the system is assumed to be concentrate Velocity of centre of mass can be changed by internal forces

E An ice block with some stone pieces embedded in it is floating in a water tank If ice melts the level of water in the tank 1 Increases 2 Decreases 3 Remains constant 4 Can t be said 1 g 3

Four rods of equal lengths AB BC CD and DA have mass m 2m 3m and 5m respectively are placed in x y plane see figure given AB BC CD DA 4 meters The centre of mass of the system is satisfy x and y are in meters YA D 5m 3m C 2m X

18 19 20 21 22 23 24 25 26 27 28 dx A 0 d 2 dx A log 2 dx A 2 cos 2x x A B 1 B 1 C 2 D 0 Differentiate y 3x w r t x A 12x 4x 10 B 12x 4X10X C 12x 4x 10 D 2x 4x 10 d sin 2 x B cos 2x A 3 units Find the speed S t 6t 15 A 5 m s The value of x dx A cos 2x dx A 0 B x C 2 x D 2 x Displacement of a body is given by x 1 2t 3t The value of instantaneous acceleration is given by A 4 units B 6 units C 5 units D 2 units A car moves along a straight line whose equation is given by S 12 t 3t 20 where s is in metre and t is in second The velocity of the car at start will be A 7 m s D 16 m s B 6 m s C X B 9 m s C 12 m s A particle moves along a straight line such that its displacement s at any time t is given by S t 6t2 3t 4 The velocity of the particle when its acceleration is zero B 8 units C 6 units of a car at t 4s given distance C 2 m s B The value of sin x dxis A 0 B 1 3 C 2 sin 2x B 1 D 2x C 3 C 1 D sin 2x C 1 2 D 2 metre is defined by D 9 units D 15 m s D 2 D 1 2

2 A uniform thin rod of mass m and length equal to the diameter of earth is kept normally to the surface of earth The magnitude of gravitational force acting on the rod will be M mass of earth R Radius of earth 1 mg 3 mg 3 4 mg mg 2 to

A force of 20N is applied to a block at rest as shown in figure After the block has moved a distance of 8m to the right the direction of horizontal component of the force F is reversed in direction Find the velocity with which block arrives at the starting point V 2 F 1 3 16 7 3 8 7 3 2 4 5 7 3 28 3 0 25 m 2kg 37

whose curved portions are semicircules of radius 1 m The adjacent graph describes the variation of speed of the car with distance moved by it starting from point P The time t required for the car to complete one lap is equal to 6K second Find K take ln 2 2 A 4 C 12 Im S 0 2m Figure 1 112 B 8 D 16 1m

A uniform electric field having strength E is existing in x y plane as shown in figure Find the p d between origin O A d d 0 Z OJO 1 Ed cose sin0 3 2Ed M A d d 0 X 2 Ed sin0 cos0 4 None of these

2 A uniform rod OA of mass m and length L is hinged at end O with the ceiling and other end A of the rod is attached with a thread which is attached with horizontal ceiling at point P If end A of the rod is slightly displaced horizontally and perpendicular to the rod and released then time period of small oscillations will be 1 T 27 3 T 27 m L L sine 3g 2Lsin0 2 T 2 4 T 2T 2L sine g Lsine

Dor Choose the incorrect statement with regards to gravitational force 1 Gravitational force is unaffected by the intervening medium between two masses 2 Acceleration due to gravity decreases non linearly with height above earth s surface 3 Kepler s law of areal speeds is based on principle of conservation of linear momentum 4 Total mechanical energy of an orbiting satellite increases with distance from the earth s surface

An object which is thrown or projected into the air subject to only the acceleration of gravity is called a projectile and its path is called its trajectory This curved path was shown by Galileo to be a parabola Parabola is represented by a polynomial If the polynomial to represent the distance covered is p t 51 40t 1 2 What is the degree of the polynomial a 0 b 1 c 2

stion 13 The refinery plant storing crude oil in a storage tank made up of carbon steel of density 7 53 g cm is exposed of an area 0 097 cm to the environment for 358 days so that 0 175 grams of the material is lost by corrosion Find the corrosion rate in mm year Write the answer in 2 decimal point

98 Resultant of two vectors A and B is R Now mag nitude of vector is doubled keeping direction same then magnitude of the resultant becomes B Angle between vector A and B is 120 Then magnitude of A is equal to A B C B 2 B 2 B D 4 B

A coil of resistance R and self inductance L is connected to a battery of emf E through a switch S The switch is closed at t 0 Calculate the rate of increase of current at the moment when current is one third of its maximum value

An HCl molecule has rotational translational and vibrational motions If the rms velocity of HCl molecules in its gaseous phase is v m is its mass and kg is Boltzmann constant ther its temperature will be B mv 2019 Main 9 April 1 a 3k A mi 2 Mv 7k 6k mv 330 mv 54 c FOODIT

3 Friction coefficient between block and inclined plane is H if lift is moving vertically down with constant acceleration a then the value of acceleration a so that block moves down with constant velocity is 1 4 m s2 3 1 m s2 30 a m s 2 2 m s 4 All of these