Physics Questions

4 XERCISE 10 300 gm of water at 25 C is added to 100 gm of ice at 0 C The final temperature of the mixture is 5 C E 3 5 C 11 Two spheres made of same substanno 52 2 15 1 4 0 C 4

Two balls of mass 6 kg and 8 kg move towards each other with speed 35 m s and 28 m s If collision is perfectly elastic then speed of both ball respectively is A 37 m s 26 m s B 26 m s 37 m s C 7 m s 39 m s D 39 m s 7 m s

correct How many significant figures are there in the measured value 0 0005203 07 LE CORRECT TYPE questions Each question has 4 choices 1 2 3 and 4 out of which only one is 02

4 A hallow cylinder is rotating about its axis and a man is sticking against its wall Find minimum angular speed of cylinder so that he does not fall assuming s 0 5 and radius 2m a 3 2 rad s b 10 rad s d 3 2 rpm c 6 4 rad s

8q 8q 3 W oq 4 Non Work done in moving a charge from one poi to the other inside a uniformly charge conducting sphere is 1 Always zero 3 May be zero 2 Non zero 4 None of these

Paragraph A small object mass m falls freely from rest under gravity from a height h and strikes obliquely Fixed smooth inclined plane as shown in figure The impact is elastic 1 51 The time for which object remains in air between 1st and 2nd impact 2u cos a 2u g sin a 3 Fixed Fixed inclined plane 2u sin a g 2u g 52 The displacement of object along the inclined plane between 1st and 2nd impact will be 1 8h sin a 2 4h sin a 3 8h cosec 2 4 1 55 Loss in K E of bullet m 3M m u cos E 8M 1 3m M m u cos 3 8M 56 After impact the string 1 2M gl 2 mu 2M 7 3 mu V3 57 Using the condition 1 gl 3 3 gl gl

26 The temperature gradient in a rod of 0 5 m long is 80 C m If the temperature of hotter end of the rod is 30 C then the temperature of the colder end is 1 40 C 3 10 C The ratio 2 10 C 4 0 C

A light rod carries three equal masses P Q and R as shown in figure The angular acceleration of Q in vertical position of rod If it is released from horizontal position e P e 2gl 3 O gl O 0 Q l R

For a given cell the internal resistance is found to be proportional to the current drawn from it Then which of the following is the best representation of terminal potential difference V vs current drawn from the cell C K L O

If SW is the work done against electrostatic fo in bringing of a infinitesimal small test charge q fr infinity to a point P then potential at point P is SW SW

the given circuit below calculate the ratio of charges on 6F capacitor in steady state in the circuit for the cases when switch S is open and switch S is closed 3uF 6uF 1 F www 1011 100v 021 www 1002 12

Given A and B are input terminals Logic 1 5V Logic 0 1V Which logic gate operation the following circuit does A AND Gate B OR Gate C XOR Gate D NOR Gate 50 Q A KW B WWW 50 2 Vcc 6 V R 10 Q Va 20

Under the action of a force F y x j an external agent takes a particle slowly along two paths as shown Path 2 is along OP and path 1 is along OAP All quantities are in SI units Then 0 Path 2 P 1 2 Path 1 The given force is non conservative Work done by along both the paths are some and the value is 2J

A hollow charged metallic spherical shell has radius R If the potential difference between its surface and a point at a distance 3R from the centre is V then the value of electric field intensity at a point at distance 4R from the centre is 1 3V 19R 2 V 6R 3 3V 32R 3V 16R

Do 4 4 9 A glass flask of volume 200 cm is just filled with mercury at 20 C The amount of mercury that will overflow when the temperature of the system is raised to 100 C is Yglass 1 2 x 10 5 C Ymercury 1 8 x 10 4 C 1 2 15 cm 2 2 69 cm 3 2 52 cm 4 2 25 cm Solids expand on heating because 1 2

The capacitor C shown in the figure carries zero charges initially At t 0 switch K is closed Then choose the incorrect option www HE O O K at t 0 R produces maximum heat per sec for 0 t dW du dH dt dt dt the electrostatic flux 4 between the plates of the capacitor remains same during the charging of capacitor for 0 t a magnetic compass will show deflection near the capacitor

is constructed by fixing small identical balls at the ends of a light rod of length I The dumbbell stands vertically in the corner formed by a frictionless wall and frictionless floor After the bottom end is slightly pushed towards the right the dumbbell begins to slide Value of which of the following quantities vanish when the upper ball is losing contact with the wall

3 low k A parallel plate capacitor has a uniform elect field E V m in the space between the pla If the distance between the plates is d m area of each plate is A m the energy Jc stored in the capacitor is 1 E 1 1250 1 U E Ad 2 EAd E 4 E Ad E

12 80 gm of water at 30 C is poured on a large block of ice at 0 C The mass of ice that melts is 1 30 gm 2 80 gm 3 1600 gm 4 150 gm 13 Work done in converting 1g of ice at 10 C into stoom

Q 15 An object undergoes simple harmonic motion Its amplitude is xo The speed of the object is v when its displacement Is xo 3 What is the speed when its displacement is so A V 3 C 3 2 v B 2 v D O

A between them The wavelength of the standing wave is 2 2 42 4 3 63 Prato a farm 3 P2 time 1 21 A 3 6 05 3 6 05 A 65 A small body of mass 0 10kg is executing S H M of 05 0 10 kg fo amplitude 1 0 m and period 0 20 sec The maximum force 1 31 0m dare 0 20 sec F acting on it is 1 98 596 N 3 100 20 N 2 985 96 N 4 76 23 N 1 1 06 Two trains are moving towards each other at speeds of 20 m s and 15 m s relative to the ground The first train sounds a whistle of frequency 600 Hz The frequency of the whistle heard by a passenger in the second train before the train meets is the speed of sound in air is 340 m s 2 585 Hz 52 Sy x Frror Y 3751 1 P21A 2 1 2160 2 242 A 4 3 63 A 1 98 596 N 3 100 20 N 06 af 1 600 Hz 15 m s f atte fara to 340 m s 2 985 96 4 76 23 M 2 58

Two threads are rotate about a fixed horizontal axis through its centre At the free end of one string a particle of mass m is attached and the free of the other string 3 mg 2 is pulled down with a constant force F Given R 2R and moment of inertia of the pulley 3 mR 4 about the axis of rotation is LL R S T m Then

Vm is the maximum voltage between trends of the secondary terminal of a transformer used in a half wave rectifier When the PN junction diode is reverse biased what will be the potential difference between two ends of the diode A Zero B V m 2 C Vm

Two cones A and B of equal base area and height are arranged as shown in figure A is a solid uniform cone whereas B is a hollow uniform thin conical shell without base If centre mass of the system of two cones lies on the common base find the MA ratio of their masses AL H

4 May be ve zero or ve potential If a unit positive charge is taken from one point 7 to another point over an equipotential surface then 1 Work is done on the charge by electric field 2 Work is done by the charge against the electric field 3 Work done is non zero constant by the field 4 No work is done by the field mly charged

Three balls A B and C are projected from ground with same speed at same angle with the horizontal The balls A B and C collide with the wall during a flight in air and all three collide perpendicularly and elastically with the wall as shown in figure If the time taken by the ball A to fall back on ground is 4 seconds and that by ball B is 2 seconds Then the time taken by the ball C to reach the ground after projection will be

A monochromatic light is travelling in a medium of refractive index n 1 6 It enters a stack of glass layers from the bottom side at an angle 0 30 The interfaces of the glass layers are parallel to each other The refractive indices of different glass layers are monotonically decreasing as n n man where nm is the refractive index of the mh slab 0 1 see the figure The ray is refracted out parallel to the interface between the m 1 th and mh slabs from the right side of the stack What is the value of m th and An m m 1 13 321 2 1 n mAn n m 1 An n 3An n 2An n An n

Two bulbs rated as 25 W 110 V and 100 W 110 V Their combination is connected to 220 V electric supply Then choose the correct option O For series combination both bulbs will work properly O For series combination first bulb will fuse For parallel combination both bulb will work properly O For parallel combination first bulb will fuse

Given diagram can never represent 1 An electrostatic field 2 A magnetostatic field 3 Field for moving charge 4 An induced electric field Which of the following quantities depend

A and B are two concentric metallic shells If A is positively charged and B is earthed then electric B O 1 Field at common centre is non zero 2 Field outside B is non zero 3 Potential outside B is positive ositive 11 A

18 Two concentric shells of masses M R and M are concentric as shown in the figure Which of the following is correct regarding the gravitational force on m due to M and M at points P Q and R a Fp 0 b Fo c FR G M M 2 Q a b GM m b d All are correct P M d at

uniform velocity in a unito field as shown in figure Hence the wire becomes 1 Positively charged at end A 2 Positively charged at end B 3 Hot due to joules heating effect 4 Neither A nor B are positively charged

Major product of the given reaction is CH T CH CH CH CH O CH CH HI Product CH CH OH and CH CH CH CH I I CH CH CH CH CH OH and CH CH I T CH CH CH CH OH and CH CH I I CH3 CH T CH CH C CH and CH CH OH

15 An imaginary graph is plotted betwee potential and distance then E electric fiel A B 1 At point A E ve 2 At point C E ve 3 At point C E ve 4 At point C E 0 tic force in h

Which of the following quantities depend on the choice of zero potential or zero potential energy 3 1 Potential at a point 2 Potential difference between two points 3 Change in potential energy 4 Potential energy of a system of two charges field of

An experiment is performed to obtain the value of acceleration due to gravity g by using a simple pendulum of length L In this experiment time for 100 oscillations is measured by using a watch of 1 second least count and the value is 90 0 seconds The length L is measured by using a meter scale of least count 1mm and the value is 20 0 cm The error in the determination of g 2014 would be A 1 7 C 4 4 B 2 7 D 2 27

24 A ball rolls off the top of a stair way with a horizontal velocity 10 10 m s If the steps are 0 25 m high and 5 m wide then the ball will hit the edge of the nth step where nis 1 6 2 2 3 4 4 3

49 Four equal masses each of mass M are placed at the corners of a square of side a The escape velocity of body from the centre O of the square is 8 2GM a 4 c 2GM 4GM a a b d a 4 2GM a

Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire No current will flow if they have 1 The same charge on each 2 The same potential 3 The same energy 4 The same field on their surfaces

b Monochromatic light passes through the double slit and causes interference Find the wavelength of the light source when the spacing of the slits is 1 2 mm the distance between the slits and the screen is 5 m and the spacing between the interference patterns is 2 mm

A prism is made of glass of refractive index 3 The refracting angle of prism is A If angle of minimum deviation is equal to A the value of A is O 30 O 45 O 60 O 90

What is the effect on the image formed by the convex lens if the central portion of the lens is wrapped in black paper as show in the figure Lens O No image is formed by remaining portion of lens O The central portion of image will be absent O There will be two images O Full image formed but will be less bright

A tank is filled with a liquid upto a height H A small hole is made at the bottom of this tank Consider t be the time taken to empty first half of the tank and to be the time taken to empty rest half of the tank t Then determine the ratio

a The young s experiment was conducted using a green light source with a wavelength of 550 nm When the distance between the slit and the screen is 1m and the distance between the two slits is 15 m how far would the third bright pattern be from the centerline

Interference fringes were produced in YDSE using light of wavelength 5000 When a film of transparent material with 2 5 x 10 3 cm thick was placed over one of the slit opening the fringe pattern shifted by distance equal to 20 fringe width The refractive index of film mater O 1 2 O 1 3 O 1 4 O 1 5

180 A compound microscope has a magnification of 30 when final image is formed at 25 cm from the eye piece What is magnification produced by the objective if the focal length of eyepiece is 5 cm 05 0 072 10 0

A ventilated room has a temperature of 15 C What happened to the speed of sound if the temperature is doubled every 10 minutes Using the equation complete the table below and construct a graph to show the relationship between temperature and speed of sound Interpret the data and your conclusion EXPLORE Table 1 Speed of Sound and Temperature Room temperature every 10 minutes C 15 C 30 C 45 C 60 C 75 C Speed of Sound s w Speed of Sound m s Graph here Temperature every 10 minutes C

11 A pair of spur gears consists of a 24 teeth pinion rotating at 1000 rpm and transmitting power to a 48 teeth gear The module is 6 mm while the face width is 60 mm Both gears are made of steel with an ultimate tensile strength of 450 N mm They are heat treated to a surface hardness of 250 BHN Assume that velocity factor accounts for the dynamic load Calculate LO 6 7 i beam strength ii wear strength and iii the rated power that the gears can transmit if service factor and the factor of safety are 1 5 and 2 respectively

An object is placed at a distance x from a convex lens The power of the lens required to have an image real times magnified is n 1 nx nx n 1 nx n 1 On 1 nx

A person can see clearly upto a distance of 30 cm He wants to read a book placed at distance of 50 cm from his eyes What is power of lens required for spectacles O 2 0 D O 1 33 D O 1 0 D O 1 50 D