General Questions and Answers

110 A black body radiates energy at the rate of E watt m at a high temperature T K When the T temperature is reduced to K the radiant energy will be E 2 3 4 E 4 16 E 40

Pre Medical Physics 143 114 The range of a projectile when fired at 75 to the horizontal is 0 5 km What will be its range when fired at 45 with the same speed 1 0 5 km 2 1 0 km 3 1 5 km 4 2 0 km

7 Equal volume of H O and He gases are at same temperature and pressure Which of these will have large number of molecules 1 H 2 0 3 He

1 60 m 3 30 m 2 50 m 4 40 m KN0108 08 The velocity time graph of an object is shown The displacement during the interval 0 tot is 1 Area A Area B Area C Area D Area E 2 Area A Area C Area B Area D 3 Area A Area B Area C Area D 4 Area A Area C Area E Area B Area D ce02 080 BA TARGETPHYENG MODULED103 KINEMATICS03EXERCSEP

101 A body is in thermal equilibrium with the surrounding 1 It will stop emitting heat radiation 2 Amount of radiation emitted and absorbed by it will be equal 3 It will emit heat radiation at faster rate 4 It will emit heat radiation slowly

1 8 points You are given a solution that consists of 0 05 M of two cations barium and calcium From each of the following reagents below which would be best to use to separate Ba2 and Ca2 from the solution Explain your reasoning and show you work for all reagents a d 2 0 10 M NaCl aq 3 0 05 M Na2SO4 aq 4 0 001 M NaOH aq 5 0 50 M Na2CO3 aq

84 Fig shows the displacement of a particle moving along x axis as a function of time The acceleration of the particle is zero in the region a AB ld CD displaceme D Select correct alternative 1 a b 3 b d time b BC d DE 2 a c 4 c d

07 Velocity time v t graph for a moving object is shown in the figure Total displacement of the object during the time interval when there is non zero acceleration and retardation is v m s 202 1 60 m 3 30 m 34 2 NW 0 1020 30 40 50 sec 2 50 m 4 40 m

the 106 Two spheres of radii in the ratio 1 2 and densities in the ratio 2 1 and of same specific heat are heated to same temperature and left in the same surrounding Their rate of falling temperature will be in the ratio 1 2 1 by it 2 1 1 B0BA ARGETUNYENGMODUE 0301 1

de Broglie wavelength of electron present in He orbit is 6na a 0 529 A If electron transit in lower energy level then select the correct statement s A Number of lines in Balmer region of emission spectrum is 4 B Number of spectral lines in visible region of emission spectrum is 4 C Minimum wavelength of quanta emitted is approximately 23 4 nm D Maximum wavelength of quanta emitted is approximately 1862 nm

101 Figure below shows the velocity time graph of a one dimensional motion Which of the following characteristics of the particle is represented by the shaded area 1 Speed 2 Displacement 3 Acceleration

ALLEN 98 A ball is dropped from the certain height on th surface of glass It collides elastically and comes bac to its initial position If this process it repeated the the velocity time graph is Take downward direction as positive 1 2 3 velocity velocity T velocity 2T 1 144 2T KN000

7 The ratio of the distances traversed in succes intervals of time by a body falling from rest an 1 1 3 5 7 9 2 2 4 6 8 10 3 1 4 7 10 13 4 None of these

5 0 104 On increasing the temperature of a black body wavelength for maximum emission 1 Shifts towards smaller wavelength 2 Shifts towards greater wavelength 3 Does not shift

pdf Four indentical calorimeters painted in different colours are heated to same temperature and then allowed to cool in vacuum Which will cool fastest lo 1 One which is painted bright 2 One which is painted thick white 3 One which is painted thick black 4 One which is painted bright white

109 The temperature of a perfect black body is 727 C and its area is 0 1 m If stefan s constant is 5 67 x 10 watt m K then heat radiated by it in 1 minute is 1 8100 cal 3 810 cal 2 81000 cal 4 81 cal

142 Pre Medical Physics 103 The variation of velocity of a particle moving along 106 Ad a straight line is illustrated in the figure The distance transvered by the particle in 4 seconds is co v m s 20 10 A B C D C HIGE E

2 AB and BC 3 OA and ABC 4 OAB and BC KN0097 7 For the motion of a particle acceleration time graph is shown in figure The velocity time curve for the duration of 0 4 seconds is 202 N velocity INUADO m vebcity in m s a in m s 3210 MyTa 4 8 9

2 ALLEN 102 Which of the following statement is correct for ideal black body 1 This absorbs visible radiation only 2 This absorbs infrared radiation only 3 This absorbs half of radiation only and reflects the half 4 This totally absorbs heat radiation of all the

Solvelancer Test From the periodic table choose the non metallic elements with less than 6 valence electrons and arrange them in decreasing order of their outermost electron Solvelancer Test a Carbon Phosphorus Selenium b Lead Aluminium Sulphur c Phosphorus Carbon Hydrogen d Nitrogen Tellurium Tin a b

We consider the radiation emitted by the human body Which of the following statements is true 1 The radiation is emitted during the summers and absorbed during the winters 2 The radiation emitted lies in the ultraviolet region and hence is not visible 3 The radiation emitted is in the infra red region 4 The radiation is emitted only during the day

KN0091 91 A rocket is launched upward from the earth is surface whose velocity time graphs shown in figure Then maximum height attained by the rocket is 1000 v ms 20 40 60 80 100 120 1 1 km 3 100 km B 140 92 In above question height before retardation is 1 1 km 3 20 km 2 10 km 4 60 km KN0092 covered by the rocket 2 10 km 4 60 km Session 20 93 In above question mean velocity of rocket during the time it took to attain the maximum height 1 100 m s 2 50 m s 3 500 m s 4 25 3 m s KN0094 94 In above question the retardation of rocket is 1 50 m s 2 100 m s 3 500 m s 4 10 m s KN0095 95 In above question the acceleration of rocket is 1 50 m s 2 100 m s 3 10 m s 4 1000 m s 2 KN0096 3 4

3 8 4 m s 4 None of above KN0089 From the following velocity time graph of a body the distance travelled by the body and its displacement during 5 seconds in metres will be 40 30 20 10 C 10 20 velocity m sec 30 40 1 75 75 3 110 110 15 t in sec 2 110 70 4 110 40 KN0090

10095 75 C to 70 C T and from 94 Shown below are the black body radiation curves at temperatures T and T T T Which of the following plots is correct T T HT0096 ress relation imum energy 4 The radiation is emitted only during the day HT0101 1

ALLEN 107 A black body at 200 K is found to emit maximum 113 energy at a wavelength 14 um When its temperature is raised to 1000 K then wavelength at which maximum energy emitted is

The Wein s displacement law express relation between 1 Wavelength corresponding to maximum energy and temperature 2 Radiation energy and wavelength 3 Temperature and wavelength 4 Colour of light and temperature

91 A rocket is launched upward from the earth surface whose velocity time graphs shown in figure Then maximum height attained by the rocket 1000 v ms B 140 20 40 60 80 100 120 1 1 km 3 100 km 2 10 km 4 60 km t s C KN009

87 A liquid in a beaker has temperature 0 at time t 92 and 0 is temperature of surroundings then according to Newton s law of cooling correct graph between log 0 0 and tis 0 0 log 0 0 1 log 0 0 log 9 8 93 Session HT0095

Vapor Pressure and Boiling Point When water is in the liquid state some of the water molecules will have enough kinetic energy to escape from the surface of the water in the form of water vapor gas The pressure resulting from this gas is called the vapor pressure If the temperature gets high enough the vapor pressure will be the same as the atmospheric pressure At this point the liquid will boil Nothing will happen O The water will disappear instantly O The water will boil O The water will catch on fire Submit What will happen if you put some 20 C water in a vacuum chamber and reduce the pressure to less than 18 mmHg View Available Hint s Part C LO 12 of 28 Review Constants I Periodic Table A sealed glass jar has a small amount of water on the bottom The rest of the volume in the jar is taken up by helium gas at a partial pressure of 526 mmHg and water vapor If the total pressure inside the jar is 760 mmHg what is the temperature of the water Express your answer to three significant figures and include the appropriate units View Available Hint s

88 A person walks along an east west street and a graph of his displacement from home is shown in figure His average velocity for the whole time interval is x meter 40 20 20 40 1 0 3 8 4 m s 9 12 15 18 19 21 t sec 2 23 m s 4 None of above

84 95 Pre Medical Physics The radil of two spheres made of same metal are r and 2r These are heated to the same temperature and placed in the same surrounding The ratio of 102 W bl 1

d Solvelancer Test For the reaction given below NaHS HCl The correct statement is Solvelancer Test a Gives a diatomic and colurless gas b Gives a triatomic and odourless gas c Gives a diatomic and gas with rotten egg smell d Triatomic and colourless gas a b C d Solvelancer Test The given reaction is an example of CuCl aq 2AgNO3 aq Cu NO3 2 aq 2AgCl s Solvelancer Test a Substitution reaction b Double displacement reaction c Addition reaction 1

99 A cup of tea cools from 80 C to 60 C in one minute The ambient temperature is 30 C In cooling from 60 C to 50 C it will take 1 50 sec 2 90 sec 3 60 sec SS 4 48 sec HT0107

73 If a ball is thrown vertically upwards with speed u the distance covered during the last t seconds of its ascentis 1 ut 1 3 ut 29t 1 2 2gt 4 u gt t KN0073

A ball is thrown vertically upwards Assuming the air resistance to be constant and considerable 1 the time of ascent 2 the time of desent 2 the time of ascent the time of descent 3 the time of ascent the time of descent 4 the time of ascent the time of descent

ssion T0085 HT0091 84 Two spherical bodies A radius 6 cm and B radius 18 cm are at temperature T and T respectively The maximum intensity in the emission spectrum of A is at 500 nm and in that of B is at 1500 nm Considering them to be black bodies what will be the ratio of the rate of total energy radiated by A to that of B 119 emitters ture are emitted 1216 2 12 4 2 LPHYSCS02 THERMAL PHYSICS EXERCISE P

76 An object is dropped vertically down on earth The change in its speed after falling through a distance d from its highest point is 1 mgd 2 2gd 3 2 g d 4 2 mg d KN0076

138 Pre Medical Physics 72 Three different objects of masses m m and m are allowed to fall from rest and from the sam point O along three different frictionless paths Th speeds of the three objects on reaching the ground will be in the ratio of 1 m m m 3 1 1 1 2 m 2m 3m 111 4

ar lack colour 85 Star S emits maximum radiation of wavelength 420 nm and the star S emits maximum radiation of wavelength 560 nm what is the ratio of the temperature of S and S 1 4 3 2 4 3 4 3 3 4 4 3 4 1 2

8 The original temperature of a black body is 727 C Calculate temperature at which total radiant energy from this black body becomes double 1 971 K 2 1190 K 3 2001 K 4 1458 K MOISS 84

3 Water drops fall at regular intervals from a tap 5 m above the ground The third drop is leaving the ta at the instant the first drop touches the ground Hot far above the ground is the second drop at tha instant 1 1 25 m 2 2 50 m 3 3 75 m 4 4 00 KN006

45 24 63L of C H4 gas is combusted at 1atm pressure 300 C temperature then heat releases constant pressure due to combustion is 280kJ then calculate heat of combustion of 1 C H4 8 a 10 kJ c 280 kJ d 5 kJ b 20 kJ Stearic acid ICH CH CO TIT

094 me to then raph 92 HT0099 As compared to the person with white skin the person with black skin will experience 1 Less heat and more cold 2 More heat and more cold 3 More heat and less cold 4 Less heat and less cold

ave equal th wise as t the ends spectively interf 100 C essay 20 4 Of currents of the surrounding fluid HT0066 61 It is hotter at the same distance over the top of a fire than it is in the side of it mainly because 1 Air conducts heat upwards 2 Heat is radiated upwards 3 Convection takes more heat upwards 4 Convection conduction and radiation all contribute significantly transferring heat unward P65 PHYSICS EXERCISE

g 18m est drop hdrop second n KN0067 68 A body dropped from a tower reaches the ground in 4s The height of the tower is about 1 80 m 2 20 m 3 160 m 4 40 m

3 ut 29t KN0073 4 A stone falls freely such that the distance covered by it in the last second of its motion is equal to the distance covered by it in the first 5 seconds It remained in air for 1 12 s 2 13 s 4 u gt t 3 25 s 4 26 s 80

79 Ratio of radius of curvature of cylindrical emitters of same material is 1 4 and their temperature are in ratio 2 1 Then ratio of amount of heat emitted by them is For Cylinder length radius 1 2 1 2 1 1 3 4 1 4 1 4

4 Does not change with time but is different at different points of the body HT0054 49 The area of the glass of a window of a room is 10m and thickness 2 mm The outer and inner temperature are 40 C and 20 C respectively Thermal conductivity of glass in MKS system is 0 2 then heat flowing in the room per second will be 1 3x10 joules 2 2 x 10 joules 3 30 joules 4 45 joules 20233

3 Radius of two spheres of same material are 1 4 m respectively and their temperature are 4x10 and 2x10 K respectively Then ratio of emitted energy of spheres per sec will be 1 1 2 2 2 1 3 1 1 4 4 1

3 60 C 3 HT0062 57 Mud houses are cooler in summer and warmer in winter because 1 Mud is super conductor of heat 2 Mud is good conductor of heat 3 Mud is bad conductor of heat 4 None of these FT006 63