Physics Questions

2 0 cm An 20 Two charges q 3 0 C and q2 4 0 C initially are separated by a distance r external agent moves the charges until they are r 5 0 cm apart 1 How much work is done by the electric field in moving the charges from r to r Is the work positive or negative ii How much work is done by the external agent in moving the charges from r to r Is the work positive or negative

The tension in cable AB is 100 N Determine the moment about O of this tension as applied to point A of the T shaped bar The dimension b is 600 mm Select one a 72 3 N m CW b 16 5 N m CCW c 43 4 N m CW d 32 9 N m CCW b 60 B

Consider a hollow spherical conductor that has a potential of 300 volts at its outside surface The potential inside the hollow space must be a Zero at the center and rising to something less than 300 V at the edge of the hollow space b Zero at the outer part and rising to 300 volts at the center c It depends on the ratio of outer and inner radii d Zero everywhere e 300 V everywhere 150 V everywhere

ssuming Laplace s law for a spl brane derive the expression for the capillary rise of a wetting liquid OR Obtain the relation between surface tension and rise of a liquid in a capillary tube using Laplace s formula for a spherical membrane Derive an expression for capillary rise for a liquid having a concave meniscus OR 3 marks

law for a spherical mem brane derive the expression for the capillary rise of a wetting liquid OR Obtain the relation between surface tension and rise of a liquid in a capillary tube using Laplace s formula for a spherical membrane OR Derive an expression for capillary rise for a liquid having a concave meniscus 3 marks nam and of radius r partiall

If the perpendicular distance between the point application of force and the axis of rotaion is infinity Select one a No rotation unless the contact is being broken O b The rotation is not possible O c The force applied will be very much high for even a small rotation Od The rotation is possible but the moment generated is very less

d their lines of action are at equal The 30 N force P is applied perpendicular to the portion BC of the bent bar Determine the moment of P about point A P 30 N Select one a 36 4 N m CCW b 81 9 N m CW c 73 5 N m CCW d 54 7 N m CW C 1 6 m B A 1 6 m

The ionization potential for second He electron is 13 6 eV 2 27 2 eV 354 4 eV 4 100 eV An electron makes a transition from orbit n 4 to the orbit n 2 of a hydrogen atom The wave f

A body in one dimensional motion has zero speed at an instant At that instant it must have 1 Zero velocity 2 Zero acceleration 3 Non zero velocity 4 Non zero acceleration

A body of mass m accelerates uniformly from rest to v in time t The instantaneous power delivered to the body an function of time t is AIEEE 200 1 my t t Y2 myt t 3 my t 1 4 myt 4 Dow delivered to

Question48 A student of height h jumps vertically up from the squat position At the top point of the jump the students center of mass is at a height 3h 4 from the ground The average force acting on the floor during the jump prior to the moment when the student loses contact with the floor is F It is known that when the student stands on the floor the center of mass is at a height h 2 from Vedantu YOUR DESCONAL ONULUIE

18 m How much energy is lost due to air friction g 1 20 J 2 30 J 3 40 J 4 10 J An engine pumps water continuously through a hose Water leaves the hose with a velocity u and m is the mass per unit length of the water jet What is the rate at which kinetic energy is imparted to water AIPMT 2009 1 mv 2 my 3 4 bod to the lower end of a vertical spring The spring is hung from a ceiling and has force martension produced

Q23 Figure shows a ball having a charge q fixed at a point A Two identical balls having charges q and q and mass m each are attached to the ends of a light rod of length 2a The rod is free to rotate about a fixed axis perpendicular to the plane of the paper and passing through the mid point of the rod The system is released from the situation shown in figure Find the angular velocity of the rod when the rod becomes horizontal 1 2 411 2q 3rED ma 3 3xCo ma 6Eo ma 2q A 2a q q 2a

A parallel beam of light 5000 is incident at an angle x 30 with the normal to the slit plane in a young s double slit experiment Assume that the intensity due to each slit at any point on the screen is lo point O is equidistant from S and S2 The distance between slits is 1 mm A Intensity at O is 4lo B Intensity at O is zero e The intensity at a point on the screen 1m below O is 4lo D The intensity at a point on the screen 1m below O is zero S 3m

3 twice the original value Mark the correct statement In photo electric effect electrons are emitted from metal surface when light falls on it 2 the kinetic energy of photo electrons is more for light of longer wavelength in comparison to that due to shorter wavelength 3 both of the above 4 none of the above longth of light for photoelectric effect from sodium surface is 6800 A then

spheres of radii r and r are touched and separated Calculate the ratio of their i Charges iii Self energy v Surface charge density ii Potential iv Electric field at the surface

Displacement current is same as Question Type Single Correct Type 1 2 conduction current due to flow of free electron 4 conduction current due to flow of positive ions conduction current due to flow of both 3 positive and negative free charge carriers is not a conduction current but is

A particle of mass M starting from rest undergoes uniform acceleration If the speed acquired in time T is V power delivered to the particle is AIPMT Mains 2 MV T 2 1 MV2 2 T 3 MV T 4 I MV 2 T CAIRMAT Ser

31 The voltage of clouds is 4 x 106 V with respect to ground In a lightning strike lasting 100 ms a charge of 4 C is delivered to the ground The power of lightning strike is 1 160 MW 2 80 MW 3 20 MW

3 5 When the velocity of body is variable 1 Its speed may be constant 2 Its acceleration may be constant 3 Its average acceleration may be constan 4 All of these with variable speed th

27 Two charged metallic spheres of radii r and r are touched and separated Calculate the ratio of their i Charges iii Self energy v Surface charge density 28 Just outside a sharp point on a conductor we will have a larger gradually curving places on the condunt 4 Zero ii iv Potential Electric field at the surface than just outside

A sphere of mass 500 g starts moving with an acceleration of 10 m s on application of an impulsive force The force acts on it for 0 5 s Gain in momentum of sphere is 1 2 5 kg m s 3 0 05 kg m s 2 5 kg m s 4 25 kg m s

demans The heart of a man pumps 5 litres of blood through the arteries per minute at a pressure of 150 mm of mercury It density of mecrury be 13 6 x 10 kg m and g 10 m s then the power in watt is 1 3 0 INEET 20 2 1 50 3 1 70 4 2 35 under the action of a time dependent force F 2ti 31 N where and

From NC The displacement of a charge Q in the electric field E e i e 3 ezk is r a bj The work done is 1 Q ae be 2 Q ae be 3 Q e 6 e2 4 Q 2 a b V

Q 183 The radii of two columns of a U tube are r and r When a liquid of density p and angle of contact 0 0 is filled in it the level difference of the liquid in the two columns is h Find the surface tension of the liquid 2 marks

A car of mass m starts from rest and accelerates so that the instantaneous power magnitude P The instantaneous velocity of this car is proportional to 1 t P 3 1 2 2 1 2 AIPMT Mains 2012 4 Jm kg Hence the particle is displaced from posita

P Q A particle of mass m is driven by a machine that delivers a constant power k watts If the particle starts from rest the FE and and F force on the particle at time t is Basic NEET 2015 1 2mkt 1 2 2 mkt 1 2 3 mk 2 1 2 4 mkt 1 2

A particle is projected with speed u at an angle 60 with horizontal then find the speed when its angle with horizontal changes to 30 Question Type Single Correct Type 1 2 3 NIC 2 u 3 2 u colle

A body moves from rest with a constant acceleration Which one of the following graphs represents the variation of its kinetic energy K with the distance travelled x AIIMS 2016 K 1 4 2 K X body over a closed loen is zero for every force in nature Ak 3 4 4 AIIMS 2017

840 J of heat is required to raise the temperature of 2 moles of an ideal gas from 20 C to 40 C at constant pressure The amount of heat required to raise the temperature of the same gas from 40 C to 60 C at constant volume is take R 8 4 Jg mole k Options 1 504 J 2 420 J 3 840 J 630I

1 200 J 3 A vertical spring with force constant k is fixed on a table All ball of mass m at a height h above the free upper end of the spring falls vertically on the spring so that the spring is compressed by a distance d The net work done in the process is AIPMT 2007 1 mg h d k kd 3 mg h d kd kd 2 mg h d 4 mg h d kd to rest after attaining a height of

An engine pumps water continuously through a hose Water leaves the hose with a velocity v and m is the mas unit length of the water jet What is the rate at which kinetic energy is imparted to water AIPMT 20 2 my 4 m y 1 my 2 1 3 mv 2

A block of mass 50 kg is projected horizontally on a rough horizontal floor The coefficient of friction between the block and the floor is 0 1 The block strikes a light spring of stiffness k 100 N m with a velocity 2m s The maximum compression of the spring is 1 Im 2 2 m 2m s 50 kg 800 0 1 3 3 m 4 4 m quitance depends on

A body of mass 0 5 kg experience a force F 2 3x N where x in metre is the displacement from origin It is released to move along x axis from origin then its initial acceleration 15 1 2 m s2 3 4 m s 2 10 m s 4 Zero

31 10 J ii When an object is shot from the bottom of a long smooth inclined plane kept at an angle 60 with horizontal it can travel a distance x along the plane But when the inclination is decreased to 30 and the same object is shot with the ame velocity it can travel x distance Then x x will be 1 1 2 3 NEET 2019 2 1 2 3 2 1 4 1 3 direction where F is in newton and y in meter Work done by this force t

Four identical particles each of mass m and charge q are kept at the four corners of a square of length L The final velocity of these particles after setting them free will be Kq mL 2 1 5 4 Kq 4 2 1 35 1 35 1 2 3 NE 2 7 Kq mL 4 Zero From NCERT

23 A dipole is placed in constant electric field E as shown If it is released from rest from this position find the kinetic energy gained when it is parallel to electric field vector Assume dipole is small and placed in a gravity free space

during the time the particle goes up is 1 0 5 J 2 1 25 J A particle is projected at 60 to the horizontal with 1 K 2 zero AIEEE 2008 An athlete in the olympic games covers a distance of 100 m in 10 s His kinetic energy can be estimated to be in the 3 1 25 J 4 0 5 J a kinetic energy K The kinetic energy at the highest point is AIEEE 2007 3 K 4 4 K 2

2 759 A piece of cloud is having area 25 x 106 m and electric potential of 105 volts If the height of cloud is 0 75 km then energy of electric field between earth and cloud will be 1 250 J 3 1225 J D51 4 1475 From NCERT

Which of the following statement is not true 1 Work done by conservative force on an object depends only on the initial and final states and not on the path taken 2 The change in the potential energy of a system corresponding to conservative internal forces is equal to negative of the work done by these forces 3 If some of the internal forces within a system are non conservative then the mechanical energy of the system is not constant 4 If the internal forces are conservative the work done by the internal forces is equal to the change in mechanical energy When work done by force of gravity is negative Assume only gravitational force to be acting

Starting at rest a 10 kg object is acted upon by only one force as indicated in figure Then the total work done by the force is force N 30 9 10 Time 4 490 F

1 8 J 2 11 J A bullet of mass 10 g moving horizontally with a celocity of 400 ms strikes a wood block of mass 2 kg which suspended by light inextensible string of length 5 m As a result the centre of gravity of the block found to rise a vert INEET 20 distance of 10 cm The speed of the bullet after it emerges out horizontally from the block will be 1 100 ms 2 80 ms 3 120 ms 4 160 ms falling from a height of 1 km It hit the ground with a speed of 50

is 3 9 A bucket containing water of depth 10 cm is kept in a lift which is moving vertically upwards with an acceleration which is equal to 1 times acceleration due to gravity Then pressure intensity at the bottom of the bucket in kg cm 2 is 3 25 10 3 4 25 10 4 O 1 250 2 2500 ol P hd g a 10 x 10 2 X 2500 Nm 2

4 the work done by the force of gravity is 20 J in the above Is A particle of mass m is moving with speed u It is stopped by a force F in distance x If the stopping force is then 1 work done by stopping force in second case will be same as that in first case 2 work done by stopping force in second case will be 2 times of that in first case 3 work done by stopping force in second case will be 1 2 of that in first case 4 work done by stopping force in second case will be 1 4 of that in first case phuone force as indicated in figure Then the total work done

1 E 2 2 2E 3 E 4 A stone projected vertically up with a velocity u reaches a maximum height h When it is at a height 3h 4 from the ground the ratio of KE and PE at that point is consider PE 0 at the point of projectory 1 1 1 2 1 2 3 1 3 4 3 1 10cpring is stretched by 2 cm it stores 100 J of energy If it is stretched further by 2 cm the stored energy will

Three charges Q q and q are placed at the vertices of a right angled isosceles triangle as shown The net electrostatic energy of the configuration is zero if Q is equal to 1 2 9 1 2 2q 2 2 3 2q 4 q

20 A 1 C charge is uniformly distributed on a spherical shell given by the equation x y 2 25 What will be the intensity of electric field at a point 1 1 2 1 5 N C 3 112 5 N C Two charged 2 45 N C 4 Zero

4 The ratio of electric potential due to a short electric dipole at point A whose position vector w r t centre of dipole makes 60 angle with direction of dipole moment to that at point B on axial position is Both points are at same distance from the center of the dipole 1 1 3 3 1 2 2 1 1 4 2 1

The work done by the frictional force on a surface in drawing a circle of radius r on the surface by a pencil of negligible mass with a normal pressing force N coefficient of friction H is 1 4 r N 2 2 r N 3 2 N 4 zero A force F 5 2x acts on a body in x direction where x is in metres and F in newton Find the work done in displaci

The potential energy for a force field F is given by U x y sin x y Magnitude of the force acting on the particle Telegrali of mass m at 1 1 is Para pifferentiates 2 2 3 4 0 of work done in carrying a body from P to Q from