Basic Physics Questions and Answers

In the phenomenon of electric discharge through gases at low pressure the colored glow in the tube appears as a result of AIPMT 2008 1 excitation of electrons in the atoms 2 collision between the atoms of the gas 3 collisions between the charged particles emitted from the cathode and the atoms of the gas 4 collision between different electrons of the atoms of the gas

11 1 2 A negative charge is placed at some point on the line joining the two Q charges at rest The direction of motics of negative charge will depend upon the position of negative charge alone 2 magnitude of negative charge alone 3 both on the magnitude and position of negative charge 4 magnitude of positive charge no plomb of charge Number of additional electrons on it will be

C 18 The potential on the 2 r r 3 r r 4 r r 1 1 1 C 19 64 charged drops coalesce to from a bigger charged drop The potential of bigger drop will be times that of smaller drop 1 4 2 16 3 64 4 8 tential outside a uniformly charged sphere at a distance r is a being the radius of the sphere

Consider a photon gas enclosed in a volume V and in equilibrium at temperature T The photon is a massless particle so that pc a What is the chemical potential of the gas Explain b Determine how the number of photons in the volume depends upon the temperature

A network of four capacitors of capacity equal to C C C 2C C 3C and C 4C are connected to a battery as shown in the figure The ratio of the charges on C an C is AIPMT 2005 22 C H C C HH C 7

If the two plates of the charged capacitor are connected by a wire then 1 potential will become infinite 3 capacitor will get discharged 2 charge will become infinite 4 charge will become double that of earl Now connecting it in parall

The radius of the circular plates of a parallel plate capacitor is R Air is dielectric medium between the plates If the capacitance of the capacitor is equal to the capacitance of a sphere of radius R then the distance between the plates is R 4 2 R 2 3 R 4 2R

B When you have read the question and need time to solve it When you have received the question and you have to go throu it before answering When you have solved the question and need to send it to the student

You have already picked the doubt whats your immediate next step B D If the question and its solution is lengthy I will use Need time to solve template If the solution is not going to take much time I will start solving it immediately If any part of the question is not clear I will immediately ask the student to explain it before solving All of the above options are true

A capacitor of capacitance 500uF is charged at the rate of 100 C s The time in which the potential difference become 20 V is 100 s 2 50 s 3 20 s 4 10 s aloter

A B C discussion I will use the Ask student if online template to send a message the student I will solve the entire question anyway and post the solution before exiting the session

A man is inside a lift which goes up and comes down with same constant acceleration If the ratio of apparent weights in two cases is 3 1 what is acceleration of lift g 10 m s 3 3 m s 4 m s 1 5 m s

A ball moving with momentum of 15 kg ms strikes against wall at an angle of 60 with plane of wall and reflects back with same momentum at same angle The Impulse on the ball is 15 kg ms 51 36 kg ms 15 3 kg ms1 Fern

The geographic meridian is defined as The vertical plane containing the latitude circle and the axis of rotation of earth The horizontal plane containing the latitude circle and the axis of rotation of earth The vertical plane containing the longitude circle and the axis of rotation of earth The horizontal plane containing the longitude circle and the axis of rotation of earth

P Problem 4 The surfaces p 3 p 100 z 3 and p 5 p 130 z 4 5 define a closed surface a Find the enclosed volume b Find the total area of enclosing surface Ans a 6 28 b 20 7

When a horse pulls a wagon the force that causes the horse to move forward is the force Horse exerts on ground Horse exerts on wagon Wagon exerts on horse Ground exerts on horse

The electrostatic potential existing in space is given by V xy yz zx volts where x y and z are in metres The angle made by electr field Eat 2 m 2 m 2 m with positive x axis is a Then cosa 1 3 cosa 3 sin a tana 1 3 5

In compound microscope the magnification is 95 and the distance of object from objective lens 1 3 8 cm and focal length of objective is 1 4 cm What is the magnification of eye piece when final image is formed at least distance of distinct vision A 5 C 100 B 10 D None

HONCHHICHOLO C H I2 T THHITH WITH DOMOVIT 15 49 one statement of text book is two thermometers through the corks are used to note the temperature T2 of water in calorimeter and T1 of hot water in between the double walls Is it true I think both temperature will interchange I mean T2 will be T1 and T1 will be T2 please explain thank you 15 49

A hollow cylinder of mass 2kg and radius 10cm is rotatitng about its axis at 30 rpm Torque required to stop it after 2 rotations in Nm is 1 25 x 10 A B 2 25 x 10 C 1 25 x 10 4 D 2 5 10 4

1 1000 K 2 960 K 3 846K 4 754 K A scientist says that the efficiency of his heat engine which operates at source temperature 127 C and sink tempera ture 27 C is 26 then AUMS 41

A mass of an ideal gas undergoes a reversible isothermal compression Its molecules will then have compared with initial state the same i root mean square velocity ii mean mometum iii mean kinetic energy i ii iii correct 3 ii iii correct 2 i ii correct 4 i correct

Two concentric conducting spheres of radii R and 2R are carrying charges Q and 2Q respectively If the charge on inner sphere is doubled the potential difference between the two spheres will 1 Become two times 2 Become four times 3 Be halved 4 Remain same 2Q 2R 2Q borgo at P as shown in the

For an ideal gas the heat capacity at constant pressure is larger than than that at constant volume because 1 positive work is done during expansion of the gas by the external pressure 2 positive work is done during expasion by the gas against external pressure 3 positive work is done during expansion by the gas against intermolecular forces of attraction 4 more collisions occur per unit time when volume is kept constant

libih 4 0 5 H A solenoid wound over a rectangular frame If all the linear dimensions of the frame are increased by a facto 3 and the number of turns per unit length remains the same the self inductance increased by a factor of 1 3 2 9 3 27 4 63 7 A coil of inductance 2 H has a current of 5 8 A The flux in weber through the coil is 1 0 29 2 2 9 8 R L D C CIRCUIT Case I Current Growth 3 3 12 4 11 6 sir ye increased by a factor mai confusion ho rhi hai ye smiha do

3 v Vms 4 rms The rms speed of oxygen molecules in a gas is v If the temperature is doubled and the O molecule dissociate into oxygen atoms the rms speed will become Vo 1 V D F U26 1 v 2 v 2 V 2 2 2 4 4v drogen kent at room tempertaure As compared to a hydrogen molecule an

3 T T 4 any of the three is possibl Suppose a container is evacuated to leave just one molecule of a gas in it Let v and the rms speed of the gas 1 v V TIS V V a rms and v rms rms represent the average speed Vi 2 V VO2 T 4 V is undefined rms If the temperature is doubled and the O molecule dissociate into

For a solid with a small expansion coefficient 1 C C R P S 3 C is slightly greater than C P 2 C C R 4 C is slightly less than C temparture change

Rohini satellite is at a height of 500 km and Insat B is at a height of 3600 km from surface of earth then relation between their orbital velocity VR V is A VR V C VR V B VR VI D No relation

roton with kinetic energy of 1 MeV moves from south to north It gets an acceleration of 10 2 m s y an applied magnetic field west to east The value of magnetic field Rest mass of proton is moth mathongo mathon mathango 6 x 10 27 Kg 1071 mT

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

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

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

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

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 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

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

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

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

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

iii the amplitude is doubled iv the gravity at a place is decreased Solve the following numericals 1 A man riding a scooter travels a distance of 50 metres in 20 seconds What is the speed of troualled a distance of 120 km in 3 hours whereas another train B travelled TI Mi

A particle executing S H M its potential energy V S displacement graph is given by PE 24 J M 2 The value of restoring force constant is Question Type Single Correct Type 1 12 N m 2 24 N m 3 6 N m A m 48 N m 2 m

A coil of inductance 300 mH and resistance 20 is connected to a source of voltage 2V What is the value of time at which current will be 0 5Amp Question Type Single Correct Type 1 0 3s 2 0 15S 3 0 1s

Let M be the mass and L be the length of a thin uniform rod In first case axis of rotation is assing through centre and perpendicular to the length of the rod In second case axis of rotation passing through one end and perpendicular to the length of the rod The ratio of radius of yration in first case to second case is A 1 B 2 1 C D 81

1 2as If a spring extends by x on loading then the energy stored by the spring is T is the tension in the spring and K is force constant 2x T 1 2 2 T 2K The elastic potential energy of a spring 2 2K T 2x only when it is stretched

Three blocks are suspended by vertical strings from two lightweight rods of length 1 0 59 m as shown in figure If m 7 9 kg ma 3 kg and the distance x 0 23 m Neglect the masses of the rods and strings What is the mass of the block m m

If 76 eV energy is required to move a proton between two points then the potential difference between them will be 38 V 152 V 76 V