Basic Physics Questions and Answers

If both the mass and the radius of the earth decrease by 1 the value of the acceleration due to gravity w 1 3 Correct Answer 2 Your Answer 3 Status incorrect decrease by 1 increase by 1 increase by 2 remain unchanged

1 The internal energy of a gas during isothermal expansion Rat 1 increases 1 mi 2 decreases 2 3 remains constant 3 fe 4 becomes zero 4

A homogeneous non conducting rod RS rotates about an axis passing through O and perpendicular to its length The length of OR and OS are respectively a and b Charges Q and 2Q are uniformly distributed on OR and OS respectively If the magnetic moment is zero then the relation between a and b is 29 p R SE Ow bka 1 a 2b 2 b 2a 3 a b

31 A particle moves a distance x in time t according to equation x t 5 The acceleration of particle is proportional to feel oda a velocity 3 2 c distance 2 21 d asi b b distance 2 d velocity 2 3 08 a m 001 5

39 The escape valocity of a body on the surface of the earth is 11 2 km sec If the earth s mass increases to twice its present value and radius of the earth becomes half then the escape velocity becomes year af 11 2 km sec fe year and 2041 344 Dd417 418 41 Y Gal 1 5 6 km sec 2 11 2 km sec 3 22 4 km sec 4 44 8 km sec

A ray of light is incident normally on the system as shown in figure Refractive indices of different parts are shown If a 3 2 then find the angular deviation of the ray in degree produced by this system Outside medium is air F LL

36 A coil of wire of certain radius has 600 turns and a self inductance of 108 mH The self inductance of a second similar coil of 500 turns will be fait face and are 600 ali 1 74 mH ako 2 75 mH 108 500 3 76 mH 4 77 mH

carry one quarter of the load The Marina trench is located in the Pacific Ocean and at one place it is nearly eleven km beneath the surface of water The water pressure at the bottom of the trench is about 1 1 x 108 Pa A steel ball of initial volume 0 32 m is dropped into the ocean and falls to the bottom of the trench What is the change in the volume of the ball when it reaches to the bottom B is of 11km

Q 2 a Calculate Turn ratio N2 N1 for circuit given below 2 5 Marks b Also calculate primary and secondary winding inductance values to attain V 4V 2 5 Marks V 50 v cau V 429 c Calculate Turn ratio N2 N1 for circuit given below 2 5 Marks d Also calculate primary and secondary winding inductance values to attain V

A coil having N turns is wound tightly in th form of a spiral with inner and outer radii a and respectively When a current I passes through the coil the magnetic field at its centre is 1 2 3 4 HONI b 2 o NI a HONI 2 b a HONI 10 log a b a

4 The arrangement of 11 bars which are identical in nature is shown below B D A C P length of each rod A Area of cross section for each rod Thermal insulation is provided to LSA of each bar then rate of heat transfer dQ dt in each bar is Z thermal conductivity of material T1 and T2 Temperature at which A F are kept T1 being greater than T2 dQ dT JAB dQ E H dT BE dQ dT JcD 27 3XS 7 ZA dQ T F dQ dT JDG dT JCH 99 89 R

5 A potential difference is applied across the end of a metallic wire If the potential difference is doubled then drift velocity har fortfayarak CHIPI G 1 will be doubled 3 will be quadrupled 1 3 R 2 will be halved 4 will remain unchanged 2 3 4 34Rafa

Q8 Which among the following does not affect the activity of the enzyme after a particular point Anonymous Quiz 12 a Temperature 15 b PH 43 c Concentration of substrates X 30 d Competitive inhibitor

6 Which of the following statements are marjob gutwollotadi correct 1 Centre of mass of a body always coincides with the centre of gravity of the body 2 Centre of mass of a body is the point at which the total gravitational torque on the body is zero 3 A couple on a body produce both translational and rotational motion in a body villal 4 Mechanical advantage greater than one means that small effort can be used to lift a large load imatt a 2 and 4 c 2 and 3 b 1 and 2 ett 2

A ray of light travelling in water is incident on its surface open to air The angle of incidence is which is less than the critical angle Then there will be Air water 0 00 8 A Only a reflected ray and no refracted ray O Only a refracted ray and no reflected ray A reflected ray and a refracted ray and the angle between them would be less than 180 20

4 A particle moves in a circle of radius 30cm Its linear speed is given by v 2t where t is in second and in m sec Find its radial and tangential acceleration at t 3 second respectively 30cm fata a pusta t 3 1 220 m sec 50 m sec 3 100 m sec 5 m sec 2 120 m sec 2 m sec 4 110 m sec 10 m sec V

A rod of length L and mass M is acted on by two unequal forces F and F2 F as shown in the following figure F C A F B 1 F 1 1 F 2 F 1 1 F 1 3 F F K K The tension in the rod at a distance y from the end A is given by Question Type Single Correct Type

Supriya is running with a velocity V m s towards a skateboard kept on a smooth surface When she jumps onto the skateboard what will happen to her velocity A It will remain the same B It will increase C It will decrease

A person runs along a circular path of radius 5m If he completes th of the circle Find the magnitude of the displacement vector How far the person ran A 5 2m 2 5mm B 10m 57 m C 5 m 10m D 2 5mm 5 2m

Q9 25 Feb 2021 Shift 1 The same size images are formed by a convex lens when the object is placed at 20 cm or at 10 cr from the lens The focal length of convex lens is mathong mathong mathongo mathongo mothe cm

A wooden stick 2 m long is floating on the surface of water The surface tension of water 0 07 N m By putting soap solution on one side of the sticks the surface tension is reduced to 0 06 N m The net force on the stick will be A 0 07 N B 0 06 N YOU C 0 01 N 0 02 N

A galvanometer has a coil of resistance 100 2 showing a full scale deflection at 50 A What resistance should be added to use it as a a voltmeter of range 50 V an ammeter of range 10 mA

A metal plate weighing 200 g is balanced in mid air by throwing 40 balls per second vertically upwards from below After collision balls rebound with the same speed What is the speed with which the balls strike the plate Given mass of each ball 200 g 1 5 7 cm s 2 12 25 cm s 3 9 8 cm s 4 14 cm s o force of

3 In the circuit shown in figure the switch S is closed at t 0 After closing the switch in steady state the value of current in the resistor R as compared to the current through it before closing the switch R L mmmmmm 1 Increases www R R L PS 2 Decreases

38 E and E are electric field at axial point and equatorial point of an electric dipole then 2 E E 0 4 E E 0 1 E E 0 3 E E 0 figure

3 10 s A particle covers half its journey with a constant speed v half the remaining part of journey with a constant speed of 2v and the rest of journey with a constant speed of 4v Its average speed during the entire journey is 1 3 16v 11 19v 13 2 adt 4 11v 16 23v EE

A loading car as given in figure is at rest on a track forming an angle of 25 with the vertical The gross weight of the car and its load is 5000 lb and it is applied at a point 30 in from the track halfway between the two axles The car is held by a cable attached 24 in from the track Determine the tension in the cable and the reaction at each pair of wheels 24 in 25 25 in 25 in G 30 in

Three copper rods are subjected to different potential difference Compare the drift speed of electrons through them Assume that all 3 are at the same temperature Length Diameter Potential difference A B C L 21 3L OVA VB VC OVA VB VC OVA VB VC None of these 3d d 2d V 2V 2V

Siphon works when hy 0 Pressure at point 2 is P Pa pgh3 Pressure at point 3 is Po Pressure at point 1 is g OROKORXX 00 NON LELERAD Handi www ROBBAROK 14 HE andanga h

A transformer rated at a maximum of 25 kVA supplies a 12 kW load at power factor 0 60 lagging What percent of the transformer rating does this load represent How many kW in additional load may be added at unity power factor before the transformer exceeds its rated kVA

the following figure the pulley P is fixed and the pulley P2 is movable If W W 100 N what is the angle AP P The pulleys are 77 In frictionless a 30 c 90 A P2 W b 60 d 120 K P W com

Choose the correct option O Work done by external agent to take negative charge from higher potential to lower potential is negative Work done by external agent to take positive charge from lower potential to higher potential is positive O Work done by electric field on negative charge for motion from higher potential energy to lower potential energy is negative O Work done by electric field on positive charge for motion from lower potential energy to higher potential energy is positive

2 25 For the circuit shown in the figure the current through the inductor is 1 6 A while the current through the condenser is 0 4 A then the current I drawn from the source is 00000000 L 1 2 2 A 2 1 65 A 3 1 2 A 4 2 0 A 5 In the alternating current circuit shown in the figure the currents through resistor and capacitor are 3 A and 4 A respectively The current drawn from generator is 1 7 A 2 5 0 www 2 1 A

current loop consists of two identical semicircular parts ach of radius R one lying in the x y plane and the other in plane If the current in the loop is i The resultant magnetic due to the two semicircular parts at their common centre 2 2R 4R b d Moi 2R Moi 2R 6

Three identical fixed metal plates are arranged in the air at equal distances d from each other The area of each of the plates equals A The plate 1 has charge Q while plates 2 and 3 are not charged and are connected through a key K to the inductor L The distance between the plates is small compared with their size The ohmic resistance of the coil can be neglected A Just before the switch K is closed the charge on right surface of plate 2 is Q 2 B Just before the switch K is closed the charge on right surface of plate 3 is Q 2 e After the switch K is closed the maximum current in the circuit is Q Lefed Q d 2 LE A D After the switch K is closed the maximum current in the circuit is d L A L oooooo

4 In Y D S E if a liquid is filled between the space of screen and slit then Central bright fringe will shift upward 2 Central bright fringe will not shift FOURT 3 Central bright fringe will shift downward 4 Central fringe may shift downward or upward lito pre gradually

The half lives of two longest lived radioactive isotopes of phosphorus p32 and p33 are 14 days and 28 days respectively A sample has been prepared by mixing the two isotopes in the ratio of 4 1 of their atoms Initial activity of the mixed sample is 90 m curie Find the activity in m curie of the sample after 80 days Approximately to nearest integer Take In2 0 7 and e 0 14 3

The coercivity for a certain permanent magnet is 4 0 104 A m This magnet is placed inside a long solenoid of 40 turns cm and a current is passed in the solenoid to demagnetize it completely Find the current 10 A 20 A 30 A

2 If 1022 gas molecules each of mass 10 26 kg collide with a surface 2 perpendicular to it elastically per second over an area 1 m with a speed 10 m s the pressure exerted by the gas molecules will be of the order of a 104N m c 10 N m 3 The bob of a simple pendulum has mass b 108N m d 10 6 N m

9 The number of free electrons per 10 mm of an ordinary wire copper wire is about 2 x 102 If the average drift speed of the electrons is 0 25 mm sec then the electric current flowing through the wire is 1 0 08 A 2 0 8 A 3 8A 4 80 A 7 A point obiect is placed at a point P infront of a plane mirror MN then the position coordinate of the

A disc of mass M radius Ris placed a rough horizontal surface with its axis horizontal A light rod of length 2R is fixed to the disc at point A as shown in figure and a force Mg is 3 2 applied at the other end If disc starts to roll without slipping find the value of 10 min where minis minimum coefficient of friction b w disc horizontal surface required for pure rolling R 2 R 2R Mg 2

Five persons A B C D and E are pulling a cart of mass 100 kg on a smooth surface and cart is moving with acceleration 3 m s in east direction When person A stops pulling it moves with acceleration 4 m s in the west direction When person B stops pulling it moves with acceleration 27 m s in the north direction The magnitude of acceleration of the cart when only A and B pull the cart keeping their directions same as the old directions is 1 26 m s 3 25 m s 2 3 71 m s 4 30 m s

the particle 25 Two SHMs are represented by the equations y 0 15 m 100 3 and y 0 1 cost The phase difference of the velocity of particle 1 with respect to the velocity of T particle 2 is Find the value of N N

A particle with charge q moving with a momentum p enters in uniform magnetic field normally The magnetic field has mangnitude B and is confined to a region of width d where d 1 sin0 deflected by an angle 0 in crossing the field then P momentum of particle Bqd P 2 sin 0 3 sin 0 4 sin 0 p Bqd Bp qd pd Bq P Bq 90 If the particle is X X X X X X X X X X X X X X X X X

emitted from unit positive charge is a b 1 small uncharged metallic sphere is positioned exactly at a point midway between two equal and opposite point charges If the sphere is slightly displaced towards the positive charge and released then AIIMS 2011 AIIMS 2012 c 4T d 4 a it will oscillate about its original position b it will move further towards the positive charge c its electric potential energy will decrease and kinetic energy will increase d its total energy remains constant but is non zero A charge Q is divided into two parts of q and Q q If the coulomb repulsion between them when they are separated is along the line joinin x 0 y 0 z 0 a d 2qa along xdirec 13 The figure shows th charged particle 1 t region of uniform the figure What is field and the direc particles 2 3 and 20 1e a down top dow c top top dow E Hollol

The diagram shows four identical capacitors each of capacitance C Now a 2Q and 4Q charges are given simultaneously at the positions shown in the figure The value of VA VB will be A C 4C 5Q 2C B D 10Q 3C 11 4Q 2Q H

1 A certain quaternary star system consists of a central star of mass M and three smaller stars each of mass m The three smaller stars orbit the central star in the same circular orbit of radius r and have the same sense of revolution They are positioned one third of a revolution apart from one another in the orbit The period of revolution of each smaller star is A 2 C 2 pu 3 G m M G M m B 2 D 2 7 3 M G m 2 3 G M 73

52 A watch shows time as 3 25 when seen through a plane mirror then actual time will be 1 8 35 2 9 35 3 7 35 4 8 25 53 Which of the following is a vector quantity

A slightly tapering wire of length e and end radii a and b is subjected to stretching forces F F as shown in the Figure If Y is its Young s modulus The extension produced in the wire is KFC 5f Yab In equilibrium Then the value of k is 1 4

Pls explain concept behind the question A uniform cylindrical rod of mass m and density po is having a poin mass m at its bottom end The complete arrangement is just found t be in stable equilibrium at the position shown in diagram Find the valu of ratio of density of liquid to that of rod under the given condition H