Physics Questions

m 20 In the figure provided a crate of mass m sits at rest on a 20 ramp and is connected to another crate of mass 1 54 kg by a rope and pulley If the coefficient of friction is u 0 560 and 0 810 with the surface what acceleration will the mass mhave if it is slightly nudged and begins to be pulled up the ramp Assume the rope and pulley are massless 1 05 m s 2

A 10kg watermelon is shot horizontally out of a cannon at 10 m s The melon is shot from a roof 20 meters high 1 How long does it take for the melon to hit the ground use g 10 m s 2 2 How far does it travel in the x direction before hitting the ground

Two small spherical similar charged ball ve are tied with thread with the same point A as shown in figure q A 9 If one more ve similar charged ball is tied with point A distance between this two charges will not change In case of one more ve charge distance will change

13 A refrigerator works between 4 C and 30 C It is required to remove 600 calories of heat to keep the every second in order temperature of the refrigerated space constant The power required is Take 1 cal 4 2 Joules a 23 65 W b 236 5 W c 2365 W 1 OOF W n 2 1 Tc TH

mathon mathor If qf is the free charge on the capacitor plates and q is the bound charge on the dielectric slab of dielectric constant k placed between the capacitor plates then bound charge q can be expressed as mathor 1 f 1 mathongo mathongo mathongo mathongo mathon 2 ab af 1 qf mathongo mathongo mathonga mathongo mathon af 1 qf 4 qb q 1 1 mathongo mathongo mathongo mathongo 3 ab mathe

A current is flowing through the loop as shown in figure below The magnetic field at centre Ois R 7 i 16R 5 16R 1 90 7 downward 15R I 2R downward downward 7 i 15R upward

1 An observer can see through a pin hole the top end of a thin rid of height h placed as shown in figure The beaker height 3h and its radius h When the beaker is filled with a liquid upto a height 2h he can see the lower end of the rod The refractive index of the liquid is 3 3 2h 3h TE 2 3 4 1 60 cm to 2 60 cm to 4 12 cm to Telegram ne question 12 cm to

3 4 0cm 4 3 0cm An object is moving towards a concave mirror of focal length 24 cm When it is at a distance of 60 cm from the mirror its speed is 9cm s the speed of its image at that instant is 1 4 cm s towards the mirror 2 9 cm s towards the mirror 3 4 cm s away from the mirror 4 9 cm s away from the mirror

in a new system of unit the unit of mass is unit of length is 100 m and unit of time is Convert one joule into this new system 1 10 unit 2 100 unit 3 7 10 unit 4 1000 unit

ce of that lane hen ent An optical fibre is made of glass fibre of refractive index 1 5 The outer coating of the glass fibre is made of material of refractive index 2 What is the range of angles of the incident rays with the axis of the pipe for which total internal reflection inside the optical fibre takes place 2 45 1 60 3 30

A particle starts moving rectilinearly at time t O such that its velocity v changes with time t according to the equation v t2 t where t is in seconds and v is in m s The time interval for which the particle retards is A t 1 2 1 2 t 1 Marks 4 t 1

Two ships A and B A is at a separation of L north of B are given such that A st arts to move eastward with a constant speed of u and B starts to move with a speed v v u such that it always follow s A Find out after what time B is going to catch A

In trolley string arrangement a painter is holding string in hands and keeps in equilibrium the entire arrangement Mass of painter is 60 kg and mass of trolley is 20 kg What is normal force exerted by trolley floor on painter g 9 8 m s 5 1 196 N M m 2 392 N

Three conducting large plates each of area A are arranged parallel to each other a equal separation d as shown Plates 1 2 and 3 are given charges Q 7Q Q 30 and Q3 2Q respectively Thereafter space between plates 1 and 2 is filled with dielectric of K 2 and plates 1 and 3 are joined by conducting wire The electrostati energy stored in dielectric is B K Q d EA 2Q d A 3

A stone is projected from a point on the ground in such a way so as to hit a bird at height 3h and could attain a maximum height 4h above the ground If at the instant of projection the bird flies away horizontally with speed 10 m s and the stone still hits the bird while descending then the horizontal velocity of stone is A B C D an an 13h 4h 8 ms 1 15 m s 1 12 m s 1 9 m s 1

3 5 m s 4 3 m s A train is moving on a straight line with constant acceleration The front and the rear end of the train passes a standing person with velocities v and v respectively What is the instantaneous velocity of the train when sixty percent of the length of the train has passed that person 1 3 adeduo V2 3 v V 2 2 2v 3v 5

A certain charge Q is divided at first into two parts q and Q q Later on the charges are placed at a certain distance If the force of interaction between the two charges is maximum then Q q 4 1 Q q 2 1 Q q 3 1

A metal rod having a mass per unit length a carries a current I The rod hangs from two wires in a uniform vertical magnetic field as shown in the figure The wires make an angle with the vertical when in equilibriu Determine the magnitude of the magnetic field 150 18 100

Choose the correct answer 1 A solid sphere of radius R is uniformly charged with charge density p in its volume A spherical cavity of R radius is made in the sphere as shown Then 2 electric potential at the centre of sphere will be 3pR 1 880 O R 2 PHYSIC 5pR 680 3 4

Marks 4 0 A body covers first 1 3 part of its journey with a velocity of 2 m s next 1 3 part with a velocity of 3 m s and rest of the journey with a velocity 6m s The average velocity in m s of the body will be valuo is allowed

Marks 4 1 mass of M kg is suspended by a weightless string The horizontal force that is required to displace it until the string makes an angle of 45 with the initial vertical direction is Mg 2 1 Mg 2 Mg

he ratio of am is top end n figure When the h he can ve index A point object is placed at distance of 20 cm from a thin plano convex lens of focal length 15 cm The plane surface of the lens is now silvered The image created by the system is at 20cm 1 60 cm to the left of the system 2 60 cm to the right of the system 3 12 cm to the left of the system 4 12 cm to the right of the system ACDE questiongat

Here M m m m and Em r is called the first moment of the mass Further r x i y j z k and TCM XCM YCM 1 ZCM k So the cartesian coordinates of the CM will be or XCM XCM Similarly y CM m x m x mn xn mn m m 11 m x i 1 TCM i 1 M n mi Yi and ZCM m m m3 Substituting the values we get mi zi i 1 M M Example 8 4 The position vectors of three particles of mass m 1 kg m 2 kg and m3 3 kg are r 1 43 k m 1 k m and r3 21 1 2 k m respectively Find the position vector of their centre of mass 5 Sol The position vector of CM of the three particles will be given by m m M3 E3 TCM 91 33 3k 6 n mixi i 1 mi 1 4 k 2 i 3 k 3 21 3 2k 1 2 3 QB x 32 TCM 31 1 k m Example 8 5 Four particles of mass 1 kg 2 kg 3 kg and 4 kg are placed at the four vertices A B C and D of a square of side 1 m Find the position of centre of mass of the particles Sol Assuming D as the origin DC as X axis and DA as Y axis we have Y x y AO

Assertion A If there exists a coulomb attraction between two bodies both of them may not be charged Reason R In coulomb attraction two bodies are oppositely charged a Both A and R are true and R is the correct explanation of A c A is true but R is false b Both A and R are true but R is not the correct explanation of A d A is false but R is true

A rod of mass m and length 21 is connected to two massless strings as shown in figure A wooden disc of the same mass m is fixed at the mid point of th rod in such a way that the plane of the disc is perpendicular to the rod A massless wire is wrapped around the disc and it is carrying a current I There vertically upward magnetic field B at the location of disk Sense of current in the loop when seen from string P side is clockwise P The tension in the string P is A B R mg ITR B 21 Correct Answer mg ITR B 21 X

11 In the relation y ma m al ma of y is Given m mass a acceleration and Lis length 1 MLT 2 2 MT 43 the dimensions T

Determine the minimum force P required to overcome static fra friction and to lift begin 100N block A as shown in figure The weight of 20 Wedge B is 5N and the co effecient of Static friction between all surfaces is 0 4 B A

A Smooth a 2 3 m b 11 14 m c 7 23 m d 176 34 m 227 X Wall 0 60 u 12 m s m 4 2 kg k spring 2 N m A ball whose weight on moon is 16N projected on the surface of earth making angle 8 from horizontal at the highest point of its trajectory It strikes a block spring system The compression in the spring is Assume perfectly inelastic collision Given gmoon Take ge 9 8 m s SolveLancer Test

A particle of mass m is driven by a machine that delivers a constant power k watts If the particle starts from rest the force on the particle at time t is A B Correct Answer mdv dt t2 mk t 2 1 2mk t2 1 mkt EXPLANATION Fv constant k V k fvdvfdt

On heating water bubbles being formed at the bottom of the vessel detatch and rise Take the bubbles to be spheres of radius R and making a circular contact of radius r with the bottom of the vessel If r R and the surface tension of water is T value of r just before bubbles detatch is Density of water is p 4441 444444 hl 444 R 2r 44444 14444

Figure shows two plane mirrors parallel to each other and an object O placed between them Then the distance of the first three images from the mirror M will be in cm 1 5 10 15 2 5 15 30 15 25 35 5 4 5 15 25 M 5cm 15cm M

Two long straight conductors with current and 12 are placed along x and yaxes as shown in figure The equation of locus of point of zero induction is y O y x Oy 12 x Oy 1 2 x Oy 1 1 x 12 X

A solenoid has 2000 turns wound over a length of 0 30 m The area of its cross section 1 2 x 10 m Around its central section a coil of 300 turns wound If an initial current of 2 A in the solenoid is reversed in 0 25 s then the emf induced in the coil is equal to 8 6 10 V B 4 8 x 10 2 V Correct Answer 1 2 10 V 2 6 0 10 V EXPLANATION di 140 N N A de dt 4TX10 7x2000 300 1 2 10 4 Emf Mdi dt 0 3 0 25

small spherical metal ball of radius r is lying at the bottom of a stationary container containing liquid of density p as shown in the figure P mospheric pressure Force exerted by liquid on the upper hemispherical part of the sphere is 1 2 3 4 r 3 2 r 3 3Po 7rpg 3Po 4rpg Po 7rpg 2Po 7rpg 2 r 3 4r A

Given wave function for an electron magnetic wave to be y x t 10 sin 3 106 x 9 x 1014 t The speed of wave is Question Type Single Correct Type 1 2 108 m s 2 108 m s 3 3 108 m s x

In a double mass system two masses one of mass m and the other of 2m d distance apart rotate about their common centre of mass Find the value of the period of revolution in sec 10 10 Nm kg m 2 1020 kg G d 2 3 4 104 m

8 A drop of water has 550 excess electrons To keep it hanging in the air an electric field of 100 N C acting in vertically downward direction has to be applied The radius of the drop is about 1 6x 10 4 mm 3x10 4 mm 2 4 3 8x10 4 mm 1 10 4 mm 3

Convex lens made up of glass g 1 5 and radius of curvature R is dipped into the water Its focal length will be Refractive index of water 4 3 A 4R B 2R CR D R2

Susan s 11 0 kg baby brother Paul sits on a mat Susan pulls the mat across the floor using a rope that s angled 30 above the floor The tension is a constant 29 0 N and the coefficient of friction is 200 Part A Use work and energy to find Paul s speed after being pulled 3 40 m Express your answer with the appropriate units VI HA

Two friends are pulling a train cart down some tracks The first friend is pulling with a force F1 at an angle of 34 degrees from the tracks The second friend is pulling at an angle of 45 degrees with a force of F2 105 N a 10 pts If there is no net force perpendicular to the tracks what is the force F1 b 10 pts The train cart begins to accelerate down the tracks at a 0 32 m s2 What is the mass of the cart GWR Figue

None these Power of a convex lens is 5D 1 5 this lens is immersed in a liquid of refractive inde it acts like a divergent lens of focal length 10 cm Then refractive index of the liquid will be 2 e 5 3 3 6 5 teleghyn 4 None of these

A horizontal uniform glass tube of 100 cm length sealed at both ends contains 10 cm mercury column in the middle The temperature and pressure of air o either side of mercury column are respectively 31 C and 76 cm of mercury If the air column at one end is kept at 0 C and the other end at 273 C the pressure of air which is at 0 C is in cm of Hg Assume no heat flow through mercury A B C 76 Your Answer 88 2 102 4 Correct Answer 12 2 EXPLANATION o o

An observer and a vehicle both start moving together from rest towards the right with acceleration 5 m s and 2 m s 2 respectively There is a 2 kg block on the floor of the vehicle and coefficient of friction is 0 3 between their surface Then the work done by the frictional force on the 2 kg block observed by the running observer during the first 2 seconds of the motion A 24 J B 24 J 16 J 2kg 5m s

Two blocks B and C are connected with a spring of stiffness k A block A is projected with speed v as shown For what value s of I will the block D move with velocity v after all the elastic collisions are over All the blocks have mass m and surface is smooth A D A m TV E m 2k E B k 00000 C D V

Marks 4 1 Two blocks are connected by a spring The combination is suspended at rest from a string attatched to the ceiling as shown in the figure The string breaks suddenly Immediately after the string breaks what is the initial downward acceleration of the upper block of mass 2m 2m m m O

Two wires A and B made of same material and having their lengths in the ratio 6 1 are connected in series The potential difference across the wires are 3V and 2V respectively If r and are the radii of A and B respectively then IB rA 1 2 1 2 3 1 is 4 2

wo similar charge of Q as shown in figure are placed at A and B q charge is placed at point C midway between A and B q charge will oscillate if 69 B It is moved towards A It is moved towards B It is moved upwards AB

A rod of length 2 is rotating about one of its ends with angular velocity w If a magnetic field Bo exists in parallel with axis of rotation then find emf developed across the end points of rod 0 1 2B 01 O BowR 03 2B 01 5

The earth receives on its surface radiation from the sun at the rate of 1400 W m 2 The distance of the centre of the sun from the surface of the earth is 1 5 10 m and the radius of the sun is 7 0 x 10 m Treating sun as a block body it follows from the above data that its surface temperature is A B C 5801 K 10 K 50 1 K 5801 C

A charged particle having some mass is resting in equilibrium at a height H above the centre of a uniformly charged non conductin horizontal ring of radius R The force of gravity acts downwards The equilibrium of the particle will be stable