Physics Questions

A light ray is incident perpendicularly to one face to a 90 prism and is totally internally reflected at the glass air interface If the angle of reflection is 45 we conclude that the refractive index n is AIEEE 2004 H 45 45

Identify the type of force system shown in following figure Note Click on image to enlarge it F F3 F2 F4 Coplanar Concurrent force system Non Coplanar Concurrent force system

the nature of surfaces in contact and on the area in contact does not depand depands O does not depand does not depand O depands does not depand depands depands Previous Save Next

19 The resultant of called as and resultant reaction Force Applied force frictional normal reaction frictional force 2 applied force the weight of the body reaction the weight of the L 4 normal body

Question 16 The volume of a sphere having 100mm as its diameter is mm 3 523598 78 261799 39 130899 69

4 length 50 cm diameter 0 5 mm 3 length 300 cm diameter 3 mm Copper of fixed volume V is drawn into wire of length e When this wire is subjected to a constant force F extension produced in the wire is Al Which of the following graph is a straight line 4 Al versus l AIPMT 201 1 Al versus 1 2 Al versus l 3 Al versus 1 1

a A system consists of a uniformly charged sphere of radius R and a surrounding medium filled by a charge with the volume density P where a is a positive constant and r is the distance from the centre of the sphere Find the charge of the sphere for which the electric field intensity E outside the sphere is independent of R a 280 2 E 2 R My Answer Correct Answer

Question 9 To apply Lami s theorem all the Three forces in the system must be coplanar collinear forces Non collinear non concurrent forces coplanar concurrent and non colinear forces coplanar non concurrent forces

Calculate magnitude of the resultant tensile forces having of two magnitude 100N and 200N acting at an angle of 60 degrees 244 95 N 264 58 N

A rod of finite length having linear charge density A subtends an angle of 15 symmetrically at a point P which is also the centre of curvature of a circular arc having same linear charge density as shown in the figure If the net electric field at the point P is bki R then find the value of b k A B R 478

The bulk modulus of a spherical object is B If it is subjected to uniform pressure p the fractional decrease in NEET 2017 radius is 1 B 3p 2 3p B 3 P 3B 4 PB

4 Length 300 cm Diameter 3 mm 3 Length 200 cm Diameter 2mm A catapult s string made of rubber having cross section area 25 mm and length 10 cm To throw a 5 gm pabble it is stret up to 5 cm and released Velocity of projected pabble is Young coefficient of elasticity of rubber is 5 108 N m 1 20 m s 2 100 m s 3 250 m s RPMT 25 4 200 m s 9 x 101 N m Force required to increa

An oil of viscosity 0 5 stoke is flowing through a pipe of 30cm in diameter at the velocity of 4 52meter per second find reynolds number 1 stoke 10 4 m 2 per second and density of oil is 0 9 27 120 27 220 26 500 27 750

om and worm wheel number of teeth on wheel is 80 The diameters of effort and load drum are 200 mm and 100 spectively Determine velocity ratio for chine

Block A of mass m connected with spring of spring constant K is executing SHM for which x x a sinot Block B of same mass connected with spring of spring constant K is executing SHM for which x x a sino t Block B collides with block A elastically at time t 0 then displacement time equation for block A will be K wwwww A B O x a Ox a a m VK Ox a 00 E Xo a 00 K m m K TWO FOO sin co t sin co t sin co t sin co t D

Question 17 For a Weston s differential pulley block diameters of pulleys are 26 cm and 24 cm Calculate the velocity ratio 13 26 39

In an oscillating LC circuit the maximum current on the inductor is i The current in the inductor when the energy is stored equally between the electric and magnetic fields is Question Type Single Correct Type 1 1 2 2 1 3 3 1 2

3 If Assertion is true 4 If Assertion Reason both are false In the figure a ray of light is perpendicular to the face AB of a glass prism u 1 52 Find the value of 0 so that the r is totally reflected at face AC if the prism is immersed in water u 1 33 Given sin 61 0 875

J What is the velocity of a metallic ball of radius r falling in a tank of liquid at the instant when its acceleration is one half that of a freely falling body The densities of metal and of liquid are p and a respectively and the viscosity of the liquid is n 1 p 20 2 r g 20 0 91 911 pm cross section area is hang from rigid end When weight of 1 kg is hung from it then 3 p 21 8 p 0 91 4

Two point charges q and q are held fixed at d 0 and d 0 respectively of a x y co ordinate system Then which of the following statement is incorrect O The electric field E at all points on the x axis has the same direction O No work has to be done in bringing a test charge from to the origin O Electric field at all point on y axis is parallel to x axis O The dipole moment is 2 qd along the ve x axis

diagram phase can be found Ans E t Esin t B with ER 2 4E0 B 8 8 1 In Fraunhoffer diffraction the wavelength of light incident normally on the slit is where d is the width of the slit What will be the number of bright fringes formed on an infinitely extended screen placed at any distance from the slit Ans 3 maxima are formed 2 Light of wavelength 5000 A is incident on a slit of width 2 mm in Fraunhoffer diffraction

Question 20 The area of a semicircle with a diameter of 120 mm will be mm 11309 73 5654 87 3769 91 5026 55

Question 24 The unit of coefficient of friction is N kNm no unit Pascal

Question 18 Out of followings which is not vector quantity Force Speed Displacement Acceleration

A small sphere of radius r falls from rest in a viscous liquid As a result heat is produced due to viscous force Th rate of production of heat when the sphere attains its terminal velocity is proportional to 1 r 2 r NEET 2018 3 r 4 r

3 50 W 4 60 W 13 If two bulbs of power 60 W and 100 W respectively each rated 110 V are connected in series with the supply of 220 V then 1 60 W bulb will fuse 3 Both bulbs will fuse 2 100 W bulb will fuse 4 Bulbs will not fuse constant voltage source

Solve the following examples 1 How many revolutions does an electron perform before making transition from n 2 to n 1 state in hydrogen atom The average life time of first excited state in H atoms is 108 s R 1 097 x 107 m Ans 8 23 x 10 2 Calculate the wavelength and energy in eV of a photon emitted when in a hydrogen atom an electron makes a transition from the third excited state to the ground state R 1 097 x 107 m c 3 x 108 ms and h 6 625 x 10 34 Js Ans 9 72 x 108 m 12 76 eV 3 Calculate the maximum wavelength of Balmer series in the hydrogen spectrum Calculate the corresponding wave number R 1 097 x 107 m Ans 6563 1 52 106 m 4 The H line in Balmer series of the hydrogen spectrum has a wavelength 6563 From this calculate the wavelength for the first line of the Lyman series Ly Ans 1215

68 69 70 71 72 73 74 Find the acceleration of a car at t 2s given distance m is defined by S 3t 9t 18 A 24 m s 75 B 24 m s C 36 m s D 18 m s time t of the particle will be equal to zero where t is equal to The position x of a particle varies with time t as x at bt The acceleration at 2a A 76 77 3b C D zero 3b A particle moves along the x axis in such a way that its position coordinate x varies with time t according to the expression x 2 5t 6t Its initial velocity is A 3 ms B 5 ms C 2 ms D 3 ms x 4 sec 0 de A 0 Stane de A log tan 0 B log sec 0 C log cos 0 D log sin 8 The acceleration a in ms2 of a particle is given by a 3t 2t 2 where t is the time If the particle starts out with a velocity v 2 ms at t 0 then find the velocity at the end of 2 s A 36 m s B 1 C t 6t 2 t 3t 2t PARAGRAPH TYPE QUESTIONS C 1 D B 20m s C 18m s D 25m s The acceleration of a particle varies with time t seconds according to the relation a 6t 6 ms 2 Find velocity and position as functions of time It is given that the particle starts from origin at t 0 with velocity 2 ms A 3t 6t 2 t 3t 2t B 31 6t 2 t 3t 2t D 3t 6t 2 t 3t t Paragraph 1 Q No 75 to 77 The position of a body moving along a straight line is given by X 16 t 6t where X is in metre and t in second Find the position of the body at t 1s A 5m B 10 m Find the velocity of the object at any time t A V 16t 12 t 2 B V 16 121 C V 16 12 t Find the acceleration of the body at any time t A 6m s B 2 m s C 10 m s 2 C 15m D 20m D V 12 t D 12 m s 1

6 7 8 At what temperature will the average molecular kinetic energy in gaseous hydrogen be equal to the binding energy of a hydrogen atom Boltzmann constant k 1 38 x 10 23 JK Ans 1 051 x 10 K Calculate the energy required to remove an electron from Het ion Ans 54 4 eV How much energy in eV should be given to an electron in the level n 2 of a hydrogen atom so that it emit the H line of the Balmer series R 1 097 10 m c 3 x 108 ms h 6 625 x 10 34 Js Ans 2 56 eV

During Searle s experiment zero of the Vernier scale lies between 3 20 x 102 m and 3 25 x 102 m of the main scale The 20th division of the Vernier scale exactly coincides with one of the main scale divisions When an additional load of 2 kg is applied to the wire the zero of the Vernie scale still lies between 3 20 x 102 m and 3 25 x 10 2 m of the main scale but now the 45th divisio of Vernier scale coincides with one of the main scale divisions The length of the thin metallic wir is 2 m and its cross sectional area is 8 x 10 7 m The least count of the Vernier scale is 1 0 105 m The maximum percentage error in the Young s modulus of the wire is 2014

A screw gauge having 100 equal divisions and pitch of length 1 mm is used to measure the diameter of wire of length 5 6 cm If the main scale reading is 2 divisions and 47th circular division coincides with the main scale Then If pitch 1 M S D then diameter of the wire is 2 47 mm If pitch mm Clear Respo 2 If pitch mm 1 M S D then diameter of the wire is 2 47 If pitch 1 M S D then diameter of the wire is 1 47 mm x2 1 M S D then diameter of the wire is 4 47

A wire of resistance 4 Q is stretched to twice o its original length The resistance of stretched wire would be 20 40 8Q 16 Q

An RLC circuit with R 102 is connected across ac source of 200 V and angular frequency 300 rad s When only capacitance is removed the current lags behind voltage by 60 When only inductance is remove the current leads the voltage by 60 The current in the circuit is

A metal ball hangs from the ceiling by an insulating thread The ball is attracted to a positive charged rod held near the ball The charge of the ball must be C Od B 14 b negative c neutral d positive or neutral e negative or neutral

Two swimmers start swimming perpendicular to river flow with different constant speeds at the same time After reaching the opposite bank they have to walk back to reach the point exactly opposite to the starting point at the same time Assume constant walking speed for both the swimmers A Swimmer with greater speed in water will have to walk back slowly B Swimmer with smaller speed in water will have to walk back slowly C Both the swimmers will have to walk back with the same speed D It is possible for both swimmer to reach the end point simultaneously

An AC source of angular frequency o is connected with a resistance R and an uncharged capacitance C in series The potential difference across the resistor is in phase with the initial potential difference across the capacitor for the first time at the instant assume that at t 0 emf is zero G 2n TU 200

00 53 36 You are proctored by invigilator BHOLE RAJWARDHAN SANJAY XFx Note Click on image to enlarge it 200N 300 N O 129 29 N O 102 49 N O 129 29 N O 102 49 N Previous Y 100 N

A coil having 200 turns has a surface area 0 12 m A magnetic field 32 34 0 10 Wbm 2 linked perpendicular to this area changes to 0 5 Wbm2 in 0 2 s Find the average emf induced in the coil Ans 48 V

As shown in figure a rectangular loop of length L and breadth b is placed near a very long wire carrying current I The side of the loop nearer to the wire is at a distance a from the wire Find magnetic I flux linked with the loop Hint dx In x Holb L a x a dx L b x L a

Prove that the average value of an A C voltage source is given by V Vsinoot is equal for half period of its cycle The value of the A C voltage of a generator is V 0 volts at time t 0 At time to 2V T t 100 seconds the voltage V 2 volts The voltage keeps on increasing upto 100 volts After that it starts decreasing Determine the frequency of the voltage source

12 Using the expressions for charge and current for L C oscillator explain L C oscillations 13 Derive expression P Vrms Irms cosd for an A C circuit 14 Using P Vrms Irms cosd discuss the special cases for power consumed in an A C circuit 15 Explain necessity of transformer for power transmission and distribution Solve the following examples 1 Find the necessary inductance if 110 V 10 W ratting bulb is to be used with 220 V A C source having frequency 50 Hz Ans L 6 67 H 2 L 8 1 mH C 12 5 F and R 100 2 are connected in series with A C source of 230V and frequency 500 Hz Calculate voltage across the two ends of resistance Ans 230 V 3 In medium wave broadcast a radio can be tuned in the frequency range 800 kHz to 1200 kHz In L C circuit of this radio effective inductance is 200 H what should be the range of the variable capacitor Ans 88 pF to 198 pF 4 An inductor of 0 5 H and 2002 resistor are connected in series with A C source of 230 V and frequency 50 Hz then calculate 1 Maximum current in the inductor 2 Phase difference between current and voltage and time difference time lag Ans Imax 1 28 A 38 8 and 2 1 ms 73 Alternating Current

Question 15 The centroidal distance of a semicircle with R as its radius wrt its base is 4R 3 3R 4 3R 8 45R 3

Question 25 The distance of center of gravity for a hemisphere with R as its radius wrt its base is 4R 3 3R 4 3R 8 8R 3

3 With x axis westward and y axis southward the coordinates of two places are 150 m 200 m and 450 m 600 m The distance between the places is 1 200m 4 1000 2 150m 3 500m A man has to go 50 m due to North 40 m due to east and 20 m due to sout reach a field What distance he has to walk to reach the field 4 zero 1 110 m 2 50 m 3 25 m

d The relationship between the change of resistance and RTD is given by the following Eq Q 5 d RT RT20 1 20AT Where UHAN UNTU20 0 00392 for platinum UNERSITI TEKNOPerature for a platinum temperature difference between the measured temperature and the KERANA Eq Q 5 d reference temperature 20 C RT20 resistance of the sensor at the reference temperature 20 C A platinum resistance 50 C TEKNO as a resistance of 150 2 at 20 C Calculate its resistance at

7 In Young s double slit experiment if the distance between two slits is double than the wavelength of light used Prove that a maximum 5 bright fringes will be obtained on the screen 8 In Young s experiment a beam of light of wavelength 6500 and 5200 is used Find the minimum distance from the central bright fringe where bright fringes produced by both the wavelength get superposed The distance between two slits is 0 5 mm and the distance between the slits and the screen is 100 cm Ans 0 52 cm

One mole of an ideal monoatomic gas goes through a cyclic process shown in the graph Mark the correct statements V m5 T K PV diagram for the cyclic process is PV diagram for the cyclic process is D

In the circuit shown in figure 3 240 switch S is closed at time t 0 Find the current through different wires and charge stored on the capacitor at any time t S 6R www R C 3R

ply supported beam of span 4m ted to an anticlockwise couple m at the center of the beam reaction at the LHS Left t will be 1 N I

A 5m aluminium wire Y 7 x 1010 N m of diameter 3 mm supports a 40 kg mass In order to have the sam elongation in a copper wire Y 12 x 10 0 N m of the same length under the same weight the diameter should be RPMT 2007 mm 1 1 75 2 2 0 3 2 3 4 5 0