Physics Questions

The dipole moment of a current loop is independent of 1 current in the loop 3 area of the loop 2 number of turns 4 magnetic field in which it is sit

Study the given ray diagrams and select the correct statement from the following A B C D X 20 cm Screen Screen 25 cm Device X is a concave mirror and device Y is a convex lens whose focal lengths are 20 cm and 25 cm respectively Device X is a convex lens and device Y is a concave mirror whose focal lengths are 10 cm and 25 cm respectively Device X is a concave lens and device Y is a convex mirror whose focal lengths are 20 cm and 25 cm respectively Device X is a convex lens and device Y is a concave mirror whose focal lengths are 20 cm and 25 cm respectively

57 A tank full of water has a small hole at its bottom If one fourth of the tank is emptied in t seconds and the remaining three fourths of the tank is emptied in t seconds then ratio 11 is 12 a 3 c 2 2 2 b 2 d 2 3 3 BH

S 13 How large must F be in figure to give 700 g block an acceleration of 30 cm s The coefficient of friction between the two blocks and also between the block and the table is 0 15 200 g 700 g

7 An Atwood machine consists of a single pulley with masses suspended on each side It is a simplified version of many industrial systems in which counterweights are used for balance Assume that the mass on the right side is 10 kg and that the mass on the left side is 2 kg a What is the acceleration of the system b What is the tension of the cord m 2 kg m 10 kg IM 2 kg

Analyse the following observation table showing variation of image distance v with object distance u in case of a convex lens and answer the questions that follow without doing any calculations a b c S No 1 2 3 4 5 6 Object Distance u cm 100 60 40 30 25 15 Image Distance v cm 25 30 40 60 100 120 What is the focal length of the convex lens Give reason to justify your answer Write the serial number of the observation which is not correct On what basis have you arrived at this conclusion Select an appropriate scale and draw a ray diagram for the observation at S No 2 Also find the approximate value of magnification

If the image formed by a lens for all positions of an object placed in front of it is always erect and diminished what is the nature of this lens Draw a ray diagram to justify your answer If the numerical value of the power of this lens is 10 D what is its focal length in the Cartesian system

A broad source of light I 680 nm illuminates normally two glass plates 120 mm long that touch at one end and are separated by a wire 0 034 mm in diameter at the other end incident light 0 034mm 120mm The total number of bright fringes that appear over the 120 mm distance is

16 10 14C The charge to be put on a spherical conducto of radius 0 2 m to produce an electric field of 0 072 N C just above its surface is 8 10 14C hr 32 10 14C min

The instantaneous angular position of a point on a given by the equation e 2 6 rad where t is in second The magnitude of angular velocity of the point when angular acceleration becomes zero O 2 rad s O 4 rad s O 3 rad s O 6 rad s

25 A circuit has a section AB as shown in the figure If the potential differnce between two points AB is 10V A at higher potential then potential difference across 2 uF capacitor is a 9V AHHHHB SV b 7V 2 F 3 F c 12V d None

37 Four identical conducting plates are placed parallel to each other at equal separation as shown below B C 000 H Plates A and B are fixed while B and D are connected with the help of a conducting spring of spring constant k Initially the spring is in relaxed position and B and C are at rest now the spring is compressed slightly by displacing B and C and then plates B and C are released across PQ Mass of each plate is m a remains constant D b increases continuously c decreases continuously 1 2k d is varying sinusoidally with frequency 2 t m

An alpha particle of mass m suffers 1 dimensional elastic collision with a nucleus at rest of unknown mass It is scattered directly backwards losing 64 of its initial kinetic energy The mass of the nucleus is a 4m b 1 5m c 3 5m d 2m Canuary 2015

5 The acceleration of a particle moving along a straight line is defined by a as 2 The particle starts from rest at s 20m and it is observed that the velocity is 2 828 m s when s 10m Determine a value of a and b velocity when s 5m 20pts

The drift current in a p n junction is Question Type Single Correct Type 1 from the p side to the n side 2 from the n side to the p side if the junction is forward biased and in the opposi direction if it is reverse biased 3 from the n side to the p side A from the p side to the n side if the junction is forward biased and in the opposi

26 In figure there is a four way key at the middle If key is thrown from situation BD to AD then how much charge will flow through point O a 24 C c 72 C b 36 C d 12 C 22 4 F DO

A proton of mass m collides elastically with a particle of unknown mass at rest After the collision the proton and the unknown particle are seen moving at an angle of 90 with respect to each other The mass of unknown particle is m m a m b 2m c d 3 2

To increase the current sensitivity of a moving coil galvanometer we should Question Type Single Correct Type 1 decrease number of turns in coil 2 3 decrease area of cross section of the coil increase torsional constant of spiral springs

If two Resistors R and R ohms are connected in parallel in an electric circuit to make an R ohm resistor The value of R can be found from the equation 1 1 R R R If R is decreasing at the rate of 1 ohm sec and R is increasing at the rate of 0 5 ohm sec Predict the value of R at what rate is R changing when R 75 ohms and R 50 ohms

At 27 C a gas is suddenly compressed such that its volume becomes 1 8th original volume Temperature of the gas will be y 5 3 Question Type Single Correct Type 1 420 K 2 327 C 3 300 K

1 A series R C circuit is connected to an alternating voltage source Consider two situations a When capacitor is air filled b When capacitor is mica filled Current through resistor is i and voltage across capacitor is V then a i i c V Vb a Subo Doubt s b V Vb d VV 2015 a

A motor is used to deliver water at a certain rate through a given horizontal pipe To deliver n times the water through the same pipe in the same time the power of the motor must be increased as follows Question Type Single Correct Type 1 n times 2 n times 3 n times

Zener breakdown in a semi conductor diode occurs when Question Type Single Correct Type 1 Forward current exceeds certain value 2 Reverse bias exceeds certain value 3 Forward bias exceeds certain lue 4 Potential barrier is reduced to zero

A thick spherical shell of inner radius R and outer radius 2R has charge Q uniformly distributed in its volume Electric potential at center of shell is 9Q nie R Answer 1 9 0 8 2 3 Find the value of 4 5 6 7 28

For the circuit shown in figure charge flown through the switch after it is closed is n C Find the value of 1 F 4 F S L 20 V 5 4 F 1 F Answer 0 1 2 3 4 5 6 7

3 3 A gas is compressed isothermally to half its initial volume The same gas is compressed separately through an adiabatic process until its volume is again reduced to half Then NEET II 2016 compressing the gas isothermally or adiabatically willrequire the same amount of work 2 which of the case whether compression through isothermal or through adiabatic process requires more work will depend upon the atomicity of the gas 3 compressing the gas isothermally will require more work to be done 4 compressing the gas through adiabatic process will require more work to be done Loccupies a volume V at a pressure P and absolute temperature T The mass of each INEET IL 20161

The plane wall of an oven is of thickness L 0 05 m and is exposed to the surrounding at 300 K The outer surface of the oven exposed to the surrounding is at temperature 320 K in steady state The energy radiated in W m by outer surface is proportional to the temperature difference between the surface and the surrounding with proportionality constant 20 W m K What is the temperature of inner surface of the oven in steady state if the wall has a thermal conductivity of K 0 5 W m K A 400 K C 380 K B 340 K D 360 K

14 Answer the following questions based on case study Potential due to an electric dipole The electric field of a dipole at a point with position vector r depends not just the magnitude r but also on the angle between r and p Further the field falls off at large distance not as 1 r typical of the field produced by a point charge but as 1 r The electric field obeys the superposition principle Since potential is related to the work done by the field electrostatic potential also follows the superposition principle The important contrasting features of electric potential of a dipole from that due to a single charge are a The potential due to a dipole depends not just on r but also on the angle between the position vector r and the dipole moment vector p It is however axially symmetric about p That is if you rotate the position vector r about p keeping e fixed the points corresponding to P on the cone so generated will have the same potential as at P b The electric dipole potential falls off at large distances as 1 r not as 1 r characteristic of the potential due to a single charge Potential due to an electric dipole 2a i The potential due to a dipole plane 0 0 x is a Directly proportional to r and zero respectively b Inversely proportional to r and zero respectively P c Both varies as V 40 12 d None of the above ii Two charges 10 C and 10 8 C are located 15 cm apart At what distance on the line joining the two charges inside the system is electric potential zero Take the potential at infinity to be zero a 15 cm b 7 5 cm c 9 0 cm

1 2 5 2 2 3 3 1 3 4 2 7 A sample of 0 1 g of water at 100 C and normal pressure 1 013 x 105 Nm2 requires 54 cal of heat energy to convert to steam at 100 C If the volume of the steam produced is 167 1 cc the change in internal energy of the sample is NEET 2018 1 104 3 J 2 208 7 J 3 4 84 5 J 3 42 2 J In which of the following processes heat is neither absorbed nor released by a system NEET 2019

19 There are two squares loops A and B When A moves towards B a current starts flowing in B as shown in figure and current in B stops when A stops moving From that we can infer that Assume loop B is at rest b A a There is a constant current in clockwise direction in A C B There is a varying current in A There is no current in A d There is a constant current in counter clockwise direction in A

At a point on the screen in YDSE 3rd maxima is observed at t 0 Now screen is slowly moved with constant speed away from the slits in such a way that the centre of slits and centre of screen lie on same line always an at t 1 s the intensity at that point is observed to be 3 th of maximum intensity in between 2nd and 3rd maxima The speed of screen will be D 1 m Select an answer A m s 13 B m s 12 C 2 m s D 13 m s

One plano convex and one plano concave lens of same radius of curvature R but of different materials are joined side by side as shown in the figure If the refractive index of the material of 1 is and that of 2 is 2 is 1 1 1 2

A lens has a convex surface one side and a concave surface another side If the radius of curvature of convex and concave are equal to R each and u is refractive index of lens then its focal

Two charges Q and Q2 placed at 0 0 0 and a 0 0 are such that x component of field is zero at 2 a o of field will be zero at 0 0 a 2 2a 0 0 a 0 0 8 2 0 a 2a 0 0 y componer

Q A neutron having kinetic energy 12 5 eV collides with a hydrogen atom at rest Neglect the difference in mass between the neutron and the hydrogen atom and assume that the neutron does not leave its line of motion Find the possible kinetic energies of the neutron after the event

1 1 64P 3 16P 2 P AIPMT 2011 A mass of diatomic gas y 1 4 at a pressure of 2 atmospheres is compressed adiabatically so that its temperature rise from 27 C to 927 C The pressure of the gas is final state is 3 256 atm 1 28 atm 2 68 7atm 4 8 atm A thermodynamic system is taken through the cycle ABCD as shown in figure Heat rejected by the gas during the LAIPMT20121

XY6P Vo 2 4P V 3 P V A heat engine employing a Carnot cycle with an efficiency of n 10 is used as a refrigerating maching the thermal reservoirs being the same The refrigerating efficiency is RPMT 2014 1 12 2 8 3 10 4 9 of the mixtu is 300 K If atomic mass

D 1 840 K 2 280 K 3 560 K 4 373 K Root mean square speed of ideal hydrogen gas in closed chamber at 0 C is 3180 m s Its pressure will be density of hydrogen gas is 8 99 10 kg m 1 atm 1 01 x 10 N m RPMT 2010 1 1 0 atm 2 1 5 atm 3 2 0 atm 4 3 0 atm upplied to raise the temperature of 50 gm of air from 20 C to 30 C without any change in its RPMT 2011

Three large conducting sheets placed close and parallel to each other contain charges Q 2Q and 3Q respect Find the electric field at points A B C and D Q 2Q 3Q HII A B C D

The capacitance C of a capacitor is Question Type Single Correct Type 1 Independent of the charge and potential of the capacitor 2 Dependent on the charge and independent of potential 3 Independent of the geometrical configuration of the capacitor 4 Independent of the dielectric medium between the two conducting surfaces of t capacitor

Two equal charges q are placed at a distance of 2a and a third charge 2q is placed at the midpoint The potential energy of the system is 1 3 q SEDA 6q STED 7q STED 99 hs

A uniform rod of length is suspended from one end and is made to undergo small oscillations What is length of a simple pendulum which has same time period as that of rod 2 4 1

A one dimensional wave function is given by y x Va exp ax find the probability of finding the particle between x 1 a and x 2 a Select one a 0 b e 4 e 2 c e 2 d 1 e 2e4

Q11 Air is blown through a pipe AB at a rate of 15 L min The cross sectional area o the broad portion of the pipe AB is 2 cm and that of the narrow portion is 0 5 cm The difference in water level h is density of air 1 32 kg m A a 16 mm b 1 5 mm c 10 mm d 32 mm B hi water

backhoe exerts a force on a 726 45 kg pile of dirt that is resting on the ground The dirt is lifted 7 62 m and

A small particle of mass mis attached at one end of a light string of length and other end is connected to the ceiling of a satellite revolving around earth in circular orbit The satellite is at height h 2Re above earth surface The period of oscillation of mass will be Re radius of earth 2 6 3R g Zona

What is education Explain its meaning by giving suitable definitions From which word the word Education has been originated

A small object is placed at the centre of the bottom of a cylindrical vessel of radius 3 cm and height 4 cm filled completely with water Consider the ray leaving the vessel through a corner Suppose this ray and the ray along the axis of the vessel are used to trace the image Find the apparent depth of the image and the ratio of real depth to the apparent depth under the assumptions taken Refractive index of water 1 33

In Young s double slit experiment the 6th bright band with wavelength coincides with 7th dark band with wavelength 22 Then 2 is a 13 12 c 6 7 b 12 13 d 7 6

Equation of a wave travelling along x axis on string is given as y 3 sin 3 14x 314t where x and y in cm and t in second Maximum velocity of particle is 9 4 m s 1 12 3 m s 1 6 2 m s 1 8 5 m s 1