Basic Physics Questions and Answers

A ball of mass m collides another identical ball at rest obliquely as in figure If velocity of 2nd ball after the collision is 6m s then the value of coefficient of restitution is 01 2 1377 10m s

1 28 A positive charge Q is uniformly distributed throughout the volume of a dielectric sphere of radius R A point mass having charge q and mass m is fired towards the centre of the sphere with velocity v from a point at distance x from the centre of the sphere Find the minimum velocity v so that it can penetrate R 2 distance of the sphere Neglect any resistance other than electric interaction Charge on the small mass remains constant throughout the motion 71 2 Ans 2KqQ r mR R 3 r 8

The oscillating frequency of a cyclotron is 10 MHz If the radius of its Dees is 0 5 m the kinetic energy of a protor which is accelerated by the cyclotron is Kerala PET 2008 a 10 2 MeV b 2 55 MeV c 20 4 MeV d 5 1 MeV e 1 5 MeV

a A thin uniform rod AB of length a has variable mass per unit length p Po a x where x is the distance measured from A and po is constant Mass of rod is M The rod is freely pivoted at A and is hanging in equilibrium vertically when it is struck by a horizontal impuls J at B Rod complete vertical circular motion about A 0 0 The moment of inertia of the rod about an axis through A perpendicular to AB is Ma 0 A B J M 70ga The moment of inertia of the rod about an axis through A perpendicular to AB is 7 12 0a 20J Velocity of centre of mass of rod just after impulse is given is 21 pa

1 If u is the coefficient of kinetic friction is the coefficient of rolling friction and u is the coefficient of static friction then a s Uk U c Us U Uk b Ms Mk Mr d Mr Uk

If on the concentric hollow spheres of radii and R the charge o is distributed such that their surface densities are same then the potential at their common centre is O O Q R r 478 R 7 OR R r Zero Q R 7 48 R r 7

bard Competiti The 300 N crate slides down the inclined curved path from A to plane as shown in the figure If the crate has a velocity of 1 2 m s down the inclined at point A and 8 m s at B Find the work done against friction during the motion 1 860 Nm 2 987 Nm 0 500 Nm 6 m 9 m

2 34 A solid conducting sphere of radius 10cm is enclosed by a thin metallic shell of radius 20cm A charge q 20mC is given to the inner sphere Find the heat generated in the process the inner sphere is connected to the shell by a conducting wire Ans 9J

negative test charge is moving near a long straight wire carrying a current The force acting on the test charge is parallel to the direction of the current The motion of the charge is Away from the wire Towards the wire Parallel to the wire along the current

A graph is shown between power delivered to external resistance by an emf source and resistance of external circuit R The internal resistance of the circuit is equal to PA La R RR OR OR OR R R R 31 E 11

A parallel circuit consists of the two ideal inductors of inductance L and 2L and a resistance R as shown At t 0 the same current lo is flowing in both the inductors in the same direction Then choose the correct option s L eeeeeee eeeeeee 2L www R LIZ The energy stored in inductance L in steady state is 18 The energy stored inductance 2L in steady state is zero 3L12 The net heat dissipated in the resistor is 2 The net heat dissipated in the resistor is LI

tical lates citor es of the the situation shown in figure 2 295 The plates of the capacitor have plate area A lb and are clamped in the laboratory The dielectric slab is released from rest with length a inside the capacitor Neglecting any effect of friction or gravity show that the slab will execute periodic motion and find its time period Figure 2 295

97 Calculate the change in surface potential energy when n identical drops of radius r of a liquid of surface tension S combine to form a bigger drop 1 4zr S n1 3 1 3 4 r S n2 3 n 2 4z S n n1 3 4 4 S n 1 n 3

Question No 55 Single Correct A A For a reaction A s 2B A2 2B s Kc has been found to be 106 The Eis cell B D 0 177 V 0 708 V 0 0098 V 1 36 V

The potential energy of a 200 gm particle free to move along the X axis is given by V x d Maximum speed of the particle is 5 m s 2T 5 Amplitude of oscillation of particle is 2 5 m O Amplitude of oscillation of particle is 5 m Time period of SHM is sec x 2 J The total mechanical energy of the particle is 2 J then

The magnifying power of a microscope with an objective of 5 mm focal length is 400 The length of its tube is 20 cm Then the focal length of the eye piece is 1 200 cm 3 2 5 cm 2 160 cm 4 01 cm

a 52 At the height 80 m an aeroplane is moving with a 1 target At what distance from the target should the 2 bomb be dropped Given g 10 ms c 80 m d 230 m a 605 3 m b 600 m along a parabolic path y 9x in

ALLEN A bar magnet is oscillating in the earth s 8 magnetic field with a period T What happens to its period and motion if its mass is quadrupled 1 Motion remains simple harmonic with time period T 2 2 Motion remains simple harmonic with time period 2T 3 Motion remains simple harmonic with time period 4T and I af San SHA en 3 4T 4 Motion remains simple harmonic with time period nearly constant af Gledand Gull 1 can add T 2 2 can add 2T 4 da feal

Magnetic field given by B 100KT in the region defined by x y 16 and y 0 A charge particle of mass m 10 19 kg q 1 6 x 10 19 C enters at origin with velocity 6401 m s What is the angle of deviation in degree suffered by charge particle in the magnetic field V HEEN

A ray of light travelling in a transparent medium 4 of refractive index falls on a surface separating the medium from air at an angle of ncidence of 45 For which of the following value of u the ray can not undergo total internal eflection 1 1 42 3 1 40 2 1 52 4 1 50 taff at site and a year and left 45 adato fa for fi an qui stater queda PI 1 1 42 3 H 1 40 2 1 52 4 1 50

A person with defective eye vision is unable to see the objects nearer than 1 2 m He wants to read a book at a distance of 30 cm The power of lens he needed in his spectacles is 4 D 2 5 D 1 67 D 2 25 D

Consider three concentric metallic shells of radius a 2a and 3a of charges q 2q and 3q respectively switch S S2 are open 3q 2a 29 q 3a S S Question Type Multiple Correct Type 1 Charge on outermost surface is zero if S2 is closed 2 Charge on outermost surface is zero if both switch S and S are closed 3 Charge on outermost surface is 3q if only S is closed

For a conductor with increase in its temperature O O Resistance increases and resistivity decreases Resistance decreases and resistivity increases Both resistance and resistivity increases Both resistance and resistivity decreases

The resistance of a filament of a bulb increases with temperature The power dissipated in a 220V 100 W bulb when connected to 110 V power supply is O 25 W O 25 W 25 W

A car P travelling at a constant speed of 20 m s overtakes another car Q which is moving at constant acceleration of 5 ms2 Car Q starts from rest at the instant car P starts overtaking it Assuming that the length of each car is 20m the total road distance used is overtaking in

The masses of the blocks A and B are m and M respectively Between A and B there i constant frictional force F and B can slide frictionlessly on horizontal surface A is se in motion with velocity while B is at rest What is the distance moved by A relative to before they move with the same velocity

A wooden block of mass 50 g is placed on a 30 inclined floor What is the value of boundary friction if the coefficient of friction is 0 4 What is the force of the downward bend along the floor when the block is in motion An object at initial velocity is a plane

Four simple harmonic motions are superimposed on a particle given by 5 cos 20 t X 10 sin t y 01 10 cos 2 ot z 20 cos X are in x direction y is in y direction 2 is in z direction Then resulting motion of the particle will X X1 A be S H M along a straight line with amplitude 10 2 B not be S H M and particle will be moving on an ellipse C motion of particle is in plane parallel to X Z plane D motion of particle is in plane parallel to Y Z plane A

A B C and D are all dimensionally different Then which of the followin must be inconsistent OAB CD OeAB sin CD OAC

A simple circuit contain an ideal battery and a resistance R If a second resistor is placed in parallel with the first then The potential across R will decrease The current through R will decrease The current delivered by the battery will increase The current delivered by the battery may increase or decrease

Let Us Practise A Multiple choice questions Tick the correct answer 1 Andaman and Nicobar Islands are in the a Bay of Bengal b Arabian Sea 2 The shape of the Southern Plateau is a round b square physical divisions b three 3 India has a four 4 The largest state in India is a Rajasthan b Bihar 5 The smallest state in India is a Madhya Pradesh 3 Fill in the blanks b Goa c Indian Ocean c triangular c six c Punjab c Uttar Pradesh

As shown in figure if o 2 x 106C m calculate the distance such that electrons strike the plate with zero velocity PI 100 eV d electron gun inlogs te loisdog listeorol to isitmotog on silt

Question No 16 Single Correct A A A dip circle shows an apparent dip of 45 at a place where the true dip is 30 If the dip circle is rotated through 90 what apparent dip will it show A cor 2 cot 2 tan 2 ENGLISH D 45 Marks 4 00

Orbit Earth Seasons Atmosphere Ozone 1 The Earth is surrounded by a layer of air called the 2 The fifth largest planet of the solar system is 3 The Earth revolves around the Sun on its 4 The protective blanket around the Earth is the layer 5 Revolution of the Earth around the Sun causes the change of

Tick the correct answer 1 The shape of the Earth is a round b spherical c flat 2 Large areas of land on the Earth s surface are called a Continents b Oceans c Satellites 3 The movement of the Earth around the Sun is known as a Rotation b Revolution c Poles 4 One rotation of the Earth on its axis is completed in a 365 days b 6 hours c 24 hours

4 10 The dry analysis of combustion of C H 0 per 100 kmol of DRY Products y 3 3 kmol e 84 6 kmol molar masses Air 29kg kmol H 2 kg kmol C 12kg kmol O 32kg kmol N 28kg kmol What is the Air to Fuel ratio aC 4 10 C H 0 b O 3 76 N xCO yCO eN H O Select one A 16 47 B 12 75 C 13 91 D 15 80 E 15 12

The principal tensile stresses at a point are 9 80 MPa and a 40 MPa Find the magnitudes of normal tangential and the resultant stress on a plane at 20 with the major principal plane What is the angle of obliquity of the resultant stress with the major principal plane Show by means of a sketch how normal stresses a and tangential stress b set on the triangular element

A slit is cut at the bottom along the right bottom edge of a rectangular tank The slit is closed by a wooden wedge of mass m and apex angle 0 as shown in the figure The vertical plane surface of wedge is in contact with the right vertical wall of container Coefficient of static friction between these two surfaces is Hstatic To what maximum height water can be filled in the tank without leakage from slit Assume that the width of wedge inside the paper is b

14 The displacement of a wave on a string which is fixed at both ends is given by y x t A cos wt kx RA cos wt kx where R is the reflectivity Show that this may be expressed as the superposition of two standing waves of amplitudes A 1 R and A 1 R

A concave mirror is used to focus the image of a flower on a nearby well 120cm from the flower If a lateral magnification of 16 is desired the distance of the flower from the mirror should be A 8cm C 80cm B 12cm D 120cm

This section contains 35 A charged oil drop of mass 10 g and charge 10 nC is suspended between two parallel horizontal charged plates The electric field between the plates IS O 4 N C O 6 N C 10 N C 8 N C

06 An automobile of constant power P travels a distance x in time t Kinetic energy of the automobile is directly proportional to 2 1 X3 2 2 4 2

a XENON PHYSICS LAW OF MOTION to roof girder at B the other end of the wire passes over the pulley C The load is supported by the pull P on kN hangs from a pulley A A flexible wire is threaded through the pulley and attached at one end the free end of wire The angle between the two parts of the wire at A is 1200 the pull P is Neglect pulley friction and weight of the hanging pulley LLL 49 kN P b 60 60 98 kN A 196 kN B c 147 kN d 196 kN

What is black hole theory please give me in dept analysis Give me Equation of Black Hole theory and proof also the equation indept analysis And with Image also

18 y component of E field at P will be P 2 3 4 1 2 3 7 60k 14 3 2 20k 14 3 2 40k 7 2 60k 7 2 Point Charge 20 C 1 02 ALLEN 18 fa 2 3 9 fa y ZV 60k 14 3 2 20k 14 3 2 40k 7 2 60k 7 3 2 P 2 3 4 far araRT 20 C 1 02

The activity of a radioactive solution of volume 1 litre is 1200 Bq A volume AV of the same liquid has an activity 120 Bq after three half lives Then AV must be A 600 c c B 800 c c C 400 c c D 880 c c

ALLEN 31 In which of the case s we will get uniform 31 charge distribution on external spherical surface Given every object is a conductor A B C D 1 Only A B 2 Only A B C 3 Only A All thin shell having net charge q thick shell net charge zero having thick shell having net charge zero qcharge q solid sphere having net A B O D 1 2 3 f ffe fargen of centre f van a fore B ABC A q sterfar za fare atuniten fare

10 2 m faya mufas ya fa ya faya uz da ann HA OPTIONS MARK FOR REVIEW CLEAR SELECTION OA OB C Has maximum value 20 N 20 Has minimum value 10 N 10 Is equal to zero CRIER Both 1 and 2

Q6 To connect the Output of Operational AMP with the input called Feedback True False Q7 OP AMP is the best example of a Analog h Digital IC

For measuring potentiometer voltage of any circuit is preferred to voltmeter because The potentiometer is cheap and easy to handle Calibration in the voltmeter is sometimes wrong The potentiometer draws no current during measurement Range of the voltmeter is not as wide as that of the potentiometer