Radioactivity Questions and Answers

A nucleus mx emits two alpha particle and two beta particles The resulting nucleus is m 4 y n 2 m 8 y n 1 m 8 y n 2 m 8
Physics
Radioactivity
A nucleus mx emits two alpha particle and two beta particles The resulting nucleus is m 4 y n 2 m 8 y n 1 m 8 y n 2 m 8
Deuteron in its ground state has a total angular momentum J 1 and a positive parity The corresponding orbital angular momentum L and spin Scombinations are L 0 S 1 and L 2 S 0 c L 0 S 1 and L 2 S 1 b L 0 S 1 and L 1 S 1 d L 1 S 1 and L 2 S 1
Physics
Radioactivity
Deuteron in its ground state has a total angular momentum J 1 and a positive parity The corresponding orbital angular momentum L and spin Scombinations are L 0 S 1 and L 2 S 0 c L 0 S 1 and L 2 S 1 b L 0 S 1 and L 1 S 1 d L 1 S 1 and L 2 S 1
When a nucleus in an atom undergoes a radioactive decay the electronic energy levels of the atom O Change for a radioactivity but not for others O Change for B radioactivity but not for others Change for a and B radioactivity but not for Y radioactivity O Do not change for any type of radioactivity
Physics
Radioactivity
When a nucleus in an atom undergoes a radioactive decay the electronic energy levels of the atom O Change for a radioactivity but not for others O Change for B radioactivity but not for others Change for a and B radioactivity but not for Y radioactivity O Do not change for any type of radioactivity
29 64 Cu can decay by Bor B emission or electron capture It is known that Cu has a half life of 12 8 hrs with 40 probability of B decay 20 probability of decay and 40 probability of 29 64 28 64 29 electron capture The mass of 4 Cu is 63 92977 amu while Zn is 63 92914 amu and 2Ni is 63 92796 amu What is the half life for electron capture A 5 12 Hrs B 32 Hrs C 2 56 Hrs 64 30 D 16 Hrs
Physics
Radioactivity
29 64 Cu can decay by Bor B emission or electron capture It is known that Cu has a half life of 12 8 hrs with 40 probability of B decay 20 probability of decay and 40 probability of 29 64 28 64 29 electron capture The mass of 4 Cu is 63 92977 amu while Zn is 63 92914 amu and 2Ni is 63 92796 amu What is the half life for electron capture A 5 12 Hrs B 32 Hrs C 2 56 Hrs 64 30 D 16 Hrs
My and My denote the atomic masses of parent and daughter nuclei respectively in a radioactive decay The Q value for B7 decay is Q and that for decay is Q If me denotes the mass of an electron then which of the following statement is correct Q Mx My c Q Mx My 2m c O Q Q Mx My c Q Q Mx My 2me c
Physics
Radioactivity
My and My denote the atomic masses of parent and daughter nuclei respectively in a radioactive decay The Q value for B7 decay is Q and that for decay is Q If me denotes the mass of an electron then which of the following statement is correct Q Mx My c Q Mx My 2m c O Q Q Mx My c Q Q Mx My 2me c
3 3 7 x 10 Bq 4 3 7 10 Bq The half life of 92U238 undergoing a decay 4 5 x 100 years The activity of 4 g sample of 92 UZ is INCERT Pg 448 1 1 23 10 Bq 2 1 23 x 105 Bq 3 4 9 10 Bq 4 49 1 1 mg radium has 2 68 x 10 8 atoms Its half radium atoms 105 Bq IT JER 12 The ener fission is 1 200 M 2 235 M 3 20 M 4 100 13 Pick out following 1 Be acc
Physics
Radioactivity
3 3 7 x 10 Bq 4 3 7 10 Bq The half life of 92U238 undergoing a decay 4 5 x 100 years The activity of 4 g sample of 92 UZ is INCERT Pg 448 1 1 23 10 Bq 2 1 23 x 105 Bq 3 4 9 10 Bq 4 49 1 1 mg radium has 2 68 x 10 8 atoms Its half radium atoms 105 Bq IT JER 12 The ener fission is 1 200 M 2 235 M 3 20 M 4 100 13 Pick out following 1 Be acc
My and My denote the atomic masses of the parent and the daughter nuclei respectively in a radioactive decay The Q value of decay is Q and that for decay is Q If me is mass of an electron then which of the following is correct O Q My My c O Q Mx My c
Physics
Radioactivity
My and My denote the atomic masses of the parent and the daughter nuclei respectively in a radioactive decay The Q value of decay is Q and that for decay is Q If me is mass of an electron then which of the following is correct O Q My My c O Q Mx My c
3 The original weight of a certain radioactive substance is 112 grams After 3 hours it decays to 56 grams Find the half life of this substance 4 If the half life of a substance is 50 years what fraction of a 200 gram substance remains after 200 years
Physics
Radioactivity
3 The original weight of a certain radioactive substance is 112 grams After 3 hours it decays to 56 grams Find the half life of this substance 4 If the half life of a substance is 50 years what fraction of a 200 gram substance remains after 200 years
Which of the following statements is false Question Type Single Correct Type 1 2 3 4 The energy spectrum of a decay is line spectrum The energy spectrum of particles is continuous The energy spectrum of y decay is continuous The energy spectra of a y decay are line spectra
Physics
Radioactivity
Which of the following statements is false Question Type Single Correct Type 1 2 3 4 The energy spectrum of a decay is line spectrum The energy spectrum of particles is continuous The energy spectrum of y decay is continuous The energy spectra of a y decay are line spectra
29 NEET UG 2019 Odisha The rate of radioactive disintegration at an instant for a radioactive sample of half life 2 2 x109 1010 s 1 The number of radioactive atoms in that sample at that instant is 1 3 17 x 1020 3 3 17 x 1018 V MP0343 2 3 17 x 1017
Physics
Radioactivity
29 NEET UG 2019 Odisha The rate of radioactive disintegration at an instant for a radioactive sample of half life 2 2 x109 1010 s 1 The number of radioactive atoms in that sample at that instant is 1 3 17 x 1020 3 3 17 x 1018 V MP0343 2 3 17 x 1017
NEET II 2016 The half life of a radioactive substance is 30 minutes The time in minutes taken between 40 decay and 85 decay of the same radioactive substance is 11
Physics
Radioactivity
NEET II 2016 The half life of a radioactive substance is 30 minutes The time in minutes taken between 40 decay and 85 decay of the same radioactive substance is 11
36 A sample of radioactive substance decays simultaneously by two processes A and B with half lives 1 2h and 1 4 h respectively For the first half hour it decays with process A next one hour with process B and for further half an hour with both A and B If originally there are No nuclei then the Number nuclei after 2h of such decay N 1 N 28 2 3 No 26 4 No 25
Physics
Radioactivity
36 A sample of radioactive substance decays simultaneously by two processes A and B with half lives 1 2h and 1 4 h respectively For the first half hour it decays with process A next one hour with process B and for further half an hour with both A and B If originally there are No nuclei then the Number nuclei after 2h of such decay N 1 N 28 2 3 No 26 4 No 25
11 Radioactive nuclei P and Q disintegrate into R with hal lives 1 month and 2 months respectively At time t 0 number of nuclei of each P and Q is xTime at which rate of disintegration of P and Q are equal number of nuclei of R is R 600 2 1 25 x 4 1 75 x X 15 X ticles and
Physics
Radioactivity
11 Radioactive nuclei P and Q disintegrate into R with hal lives 1 month and 2 months respectively At time t 0 number of nuclei of each P and Q is xTime at which rate of disintegration of P and Q are equal number of nuclei of R is R 600 2 1 25 x 4 1 75 x X 15 X ticles and
sub A 42 Half life period of a sample is 30 min Its decay 4 fraction at instant t is and decay fraction at 5 9 instant t is then t t interval is 10 1 30 min 2 43 min
Physics
Radioactivity
sub A 42 Half life period of a sample is 30 min Its decay 4 fraction at instant t is and decay fraction at 5 9 instant t is then t t interval is 10 1 30 min 2 43 min
8 A certain substance decays to of its initial 1th 64 activity in 24 days The half life of the substance will be 1 6 days 3 3 days 2 4 days 4 2 days
Physics
Radioactivity
8 A certain substance decays to of its initial 1th 64 activity in 24 days The half life of the substance will be 1 6 days 3 3 days 2 4 days 4 2 days
Figure shows activity A of three different radioactive materials samples Labeled as I II and III verses time Using the given information Choose the correct options A Disintegration constant has maximum value for the material of sample II B Half life is maximum for the material of sample III C Disintegration constant has minimum value for the material of sample II D Half life is minimum for the material of sample III A
Physics
Radioactivity
Figure shows activity A of three different radioactive materials samples Labeled as I II and III verses time Using the given information Choose the correct options A Disintegration constant has maximum value for the material of sample II B Half life is maximum for the material of sample III C Disintegration constant has minimum value for the material of sample II D Half life is minimum for the material of sample III A
3 6 32 mm 4 5 8 mm 7 Half life of a radioactive substance is 20 min The time taken between 20 decay and 80 decay wil be min 1 20 3 30 min 2 40 min 4 25 min Met
Physics
Radioactivity
3 6 32 mm 4 5 8 mm 7 Half life of a radioactive substance is 20 min The time taken between 20 decay and 80 decay wil be min 1 20 3 30 min 2 40 min 4 25 min Met
4 tending to zero 2 12 Two radioactive sources A and B of half lives of 1 hour and 2 hours respectively initially contain the same number of radioactive atoms At the end of two hours their rates of disintegration are in the ratio of 1 1 4 3 1 2 2 1 3 Louby 4 1 1
Physics
Radioactivity
4 tending to zero 2 12 Two radioactive sources A and B of half lives of 1 hour and 2 hours respectively initially contain the same number of radioactive atoms At the end of two hours their rates of disintegration are in the ratio of 1 1 4 3 1 2 2 1 3 Louby 4 1 1
Q 16 If 10 of a radioactive substance decays in every 5 years then the percentage of the substance that will have decayed in 20 years will be 1 40 2 50 3 65 6 4 34 4
Physics
Radioactivity
Q 16 If 10 of a radioactive substance decays in every 5 years then the percentage of the substance that will have decayed in 20 years will be 1 40 2 50 3 65 6 4 34 4
0 A vessel contains a non linear triatomic gas If 50 of gas dissociate into individual atom then find new valu of degree of freedom by ignoring the vibrational mode and any further dissociation 1 2 15 3 5 25 P a 2 3 75 4 6 35
Physics
Radioactivity
0 A vessel contains a non linear triatomic gas If 50 of gas dissociate into individual atom then find new valu of degree of freedom by ignoring the vibrational mode and any further dissociation 1 2 15 3 5 25 P a 2 3 75 4 6 35
34 A graph is plotted between rate of disintegration and number of active nuclei What is half life of the radioactive substance Time in second N 1 3 s 2 3 3 in 2 s In 2 4 30 dN dt
Physics
Radioactivity
34 A graph is plotted between rate of disintegration and number of active nuclei What is half life of the radioactive substance Time in second N 1 3 s 2 3 3 in 2 s In 2 4 30 dN dt
A radioactive isotope of potassium has half life x and decays to a stable isotope of argon in a sample of moon rock If age of moon rock is y then the present ratio of potassium atoms to argon atoms is A B C 1 2x 1 2xlx 1 2xx 1
Physics
Radioactivity
A radioactive isotope of potassium has half life x and decays to a stable isotope of argon in a sample of moon rock If age of moon rock is y then the present ratio of potassium atoms to argon atoms is A B C 1 2x 1 2xlx 1 2xx 1
The activity of a sample of a radioisotope at some time is 10 7 mCi and 0 36 h later it is 7 80 mCl Determine the following a Decay constant in s 2 40 4 b Half life in h 2887 916 X How is the half life related to the decay constant h c Nuclei in the sample when the activity was 10 7 mCi
Physics
Radioactivity
The activity of a sample of a radioisotope at some time is 10 7 mCi and 0 36 h later it is 7 80 mCl Determine the following a Decay constant in s 2 40 4 b Half life in h 2887 916 X How is the half life related to the decay constant h c Nuclei in the sample when the activity was 10 7 mCi
c days the activity of a radioactive sample is 6000 dps The activity reduces to 3000 dpm her 140 days The initial activity of the sample in dps is JEE 2004 d 24000 c 3000 b 9000 The time taken for the activity of a sample of 215 At to decay
Physics
Radioactivity
c days the activity of a radioactive sample is 6000 dps The activity reduces to 3000 dpm her 140 days The initial activity of the sample in dps is JEE 2004 d 24000 c 3000 b 9000 The time taken for the activity of a sample of 215 At to decay
30 The mean lives of a radioactive substance are 1620 and 405 years for B emission and B emission respectively The time after which three fourth of a sample will decay if it is decaying both by emission and B emission simultaneously will be years Take In 2 0 693
Physics
Radioactivity
30 The mean lives of a radioactive substance are 1620 and 405 years for B emission and B emission respectively The time after which three fourth of a sample will decay if it is decaying both by emission and B emission simultaneously will be years Take In 2 0 693
A heavy nucleus having mass number 200 gets disintegrated into two small fragments of mass numbers 80 and 120 If binding energy per nucleon for parent atom is 6 5 MeV and for daughter nuclei is 7 MeV and 8 MeV respectively then the energy released in the decay will be Question Type Single Correct Type 1 200 MeV 2 220 MeV 3 220 MeV 180 Mall
Physics
Radioactivity
A heavy nucleus having mass number 200 gets disintegrated into two small fragments of mass numbers 80 and 120 If binding energy per nucleon for parent atom is 6 5 MeV and for daughter nuclei is 7 MeV and 8 MeV respectively then the energy released in the decay will be Question Type Single Correct Type 1 200 MeV 2 220 MeV 3 220 MeV 180 Mall
SolveLancer Test An element X of atomic number 98 undergoes alpha decays The constant rate of alpha decay is n particles per second Atomic mass number of X is 251 u If the element Y daughter nucleus has atomic mass of 239 u What is the mass of total number of alpha particles radiated in grams SolveLancer Test a 4 g b 12 g c 2x 10 2 g d 4 x 10 23 g
Physics
Radioactivity
SolveLancer Test An element X of atomic number 98 undergoes alpha decays The constant rate of alpha decay is n particles per second Atomic mass number of X is 251 u If the element Y daughter nucleus has atomic mass of 239 u What is the mass of total number of alpha particles radiated in grams SolveLancer Test a 4 g b 12 g c 2x 10 2 g d 4 x 10 23 g
20 Two radioactive materials X and X2 have decay constants 5 and 2 respectively If initially they have the same number of nuclei then the ratio of the number of nuclei of X to that of X will be 1 e after a time a e a b C 1 2 2 d 1 42
Physics
Radioactivity
20 Two radioactive materials X and X2 have decay constants 5 and 2 respectively If initially they have the same number of nuclei then the ratio of the number of nuclei of X to that of X will be 1 e after a time a e a b C 1 2 2 d 1 42
7 The phenomenon of radioactivity is associated with 1 Decay of nucleus 2 Fussion of nucleus 3 Emission of electrons or protons 4 Rearrangement in the extra nuclear electron
Physics
Radioactivity
7 The phenomenon of radioactivity is associated with 1 Decay of nucleus 2 Fussion of nucleus 3 Emission of electrons or protons 4 Rearrangement in the extra nuclear electron
1 A radioactive substance is being produced at a constant rate of 200 nuclei s The decay constant of the substance is 1 s After what time the number of radioactive nuclei will become 100 Initially there are no nuclei present a 1 s c In 2 s b 1 In 2 loun d 2 s S
Physics
Radioactivity
1 A radioactive substance is being produced at a constant rate of 200 nuclei s The decay constant of the substance is 1 s After what time the number of radioactive nuclei will become 100 Initially there are no nuclei present a 1 s c In 2 s b 1 In 2 loun d 2 s S
22 The radioactivity of an old sample of whisky due to tritium half life 12 5 years was found to be only about 4 of that measured in a recently purchased bottle marked 10 years old The age of sample is years
Physics
Radioactivity
22 The radioactivity of an old sample of whisky due to tritium half life 12 5 years was found to be only about 4 of that measured in a recently purchased bottle marked 10 years old The age of sample is years
At a given instant say t 0 two radioactive A B have equal activities The substance RB ratio RA of their activities after time t is e 3t If half life of A is ln 2 then half life of B is Question Type Single Correct Type 1 2 3 en 2 2 2ln 2 en 2 4
Physics
Radioactivity
At a given instant say t 0 two radioactive A B have equal activities The substance RB ratio RA of their activities after time t is e 3t If half life of A is ln 2 then half life of B is Question Type Single Correct Type 1 2 3 en 2 2 2ln 2 en 2 4
After a perfectly elastic collision of two identical balls one of which was initially at rest the velocities of both the balls are non zero The angle 0 between the final velocities in the lab frame is b a 0 T 2 c 0 0 TC 2 d T 0
Physics
Radioactivity
After a perfectly elastic collision of two identical balls one of which was initially at rest the velocities of both the balls are non zero The angle 0 between the final velocities in the lab frame is b a 0 T 2 c 0 0 TC 2 d T 0
A black body which is at a high temperature T K emitted thermal radiation at the rate of E watt m The thermal radiation emitted by a body of emissivity equal to 0 5 at temperature T 4 in NCERT Pg 295 watt m is 1 E 512 2 E14 3 E 256 4 E 128
Physics
Radioactivity
A black body which is at a high temperature T K emitted thermal radiation at the rate of E watt m The thermal radiation emitted by a body of emissivity equal to 0 5 at temperature T 4 in NCERT Pg 295 watt m is 1 E 512 2 E14 3 E 256 4 E 128
238U decays in 14 steps that together constitute the net reaction 238 U 206 Pb 60 8 He The sign represents some unknown particle particles Take 1 amu 931 5 MeV C The atomic masses of 238U 206Pb 4He are 238 050783u 205 974449u and 4 002603u respectively The Q value of the reaction is O 2 6 MeV O 4 4 MeV O 51 7 MeV 8 9 MeV k
Physics
Radioactivity
238U decays in 14 steps that together constitute the net reaction 238 U 206 Pb 60 8 He The sign represents some unknown particle particles Take 1 amu 931 5 MeV C The atomic masses of 238U 206Pb 4He are 238 050783u 205 974449u and 4 002603u respectively The Q value of the reaction is O 2 6 MeV O 4 4 MeV O 51 7 MeV 8 9 MeV k
In a radioactive reaction an unstable nucleus A dis integrates into a stable nucleus B But A is generated at a constant rate of q nucleus per second Then at steady state number of nucleus of A will be q sec A q2 Select an answer B 9 C A Parent Nucleus 9 2 B Daughter Nucleus
Physics
Radioactivity
In a radioactive reaction an unstable nucleus A dis integrates into a stable nucleus B But A is generated at a constant rate of q nucleus per second Then at steady state number of nucleus of A will be q sec A q2 Select an answer B 9 C A Parent Nucleus 9 2 B Daughter Nucleus
At any instant the ratio of the amount of radioactive substances is 2 1 If their half lives be respectively 12 and 16 hours then after two days what will be the ratio of the substances Question Type Single Correct Type 1 1 1 2 2 1 3 1 2
Physics
Radioactivity
At any instant the ratio of the amount of radioactive substances is 2 1 If their half lives be respectively 12 and 16 hours then after two days what will be the ratio of the substances Question Type Single Correct Type 1 1 1 2 2 1 3 1 2
The binding energy per nucleon of deuteron and d par respectively The energy released in the following reaction will be 1H 1H 2He4 Q x1 x2 x2 x1 O 2 x1 x2 A X X
Physics
Radioactivity
The binding energy per nucleon of deuteron and d par respectively The energy released in the following reaction will be 1H 1H 2He4 Q x1 x2 x2 x1 O 2 x1 x2 A X X
4 BA 40 40 If 10 of a radioactive material decays in 5 days then the amount of original material left after 20 days is approximately 1 60 2 65 4 82 1 60 3 70 410 fra 20 fe affer 2 65 4 75
Physics
Radioactivity
4 BA 40 40 If 10 of a radioactive material decays in 5 days then the amount of original material left after 20 days is approximately 1 60 2 65 4 82 1 60 3 70 410 fra 20 fe affer 2 65 4 75
3 250 years 4 100 years 10044 The rate of disintegration of a fixed quantity of a radioactive 6 fafter that are a face element can be increased by 1 increasing the temperature 2 increasing the pressure 3 chemical reaction 4 it is not possible 1 2 3 erfaren fafarangri 4
Physics
Radioactivity
3 250 years 4 100 years 10044 The rate of disintegration of a fixed quantity of a radioactive 6 fafter that are a face element can be increased by 1 increasing the temperature 2 increasing the pressure 3 chemical reaction 4 it is not possible 1 2 3 erfaren fafarangri 4
A radioactive sample contains two different types of radioactive nuclei A with half life 5 0 days and B with half life 30 0 days Initially the decay rate of the A type nuclei is 64 times that of B type of nuclei Their decay rates will be equal when time is n days Find the value of n
Physics
Radioactivity
A radioactive sample contains two different types of radioactive nuclei A with half life 5 0 days and B with half life 30 0 days Initially the decay rate of the A type nuclei is 64 times that of B type of nuclei Their decay rates will be equal when time is n days Find the value of n
10 A radioactive nucleus X decays to a nucleus Y with a decay constant x 0 1s X Y further decays to a stable nucleus Z with a decay constant y 1 1 s Initially there 30 are only Xs nuclei and their number is N 102 Set up the rate equations for the populations of X Y and Z The Populations of Y nucleus as a function of time is given by Ny t Nox exp 2 1 exp 2 1 Find the time at which N is maximum 2x 2y and determine the populations of X and Z at that instant
Physics
Radioactivity
10 A radioactive nucleus X decays to a nucleus Y with a decay constant x 0 1s X Y further decays to a stable nucleus Z with a decay constant y 1 1 s Initially there 30 are only Xs nuclei and their number is N 102 Set up the rate equations for the populations of X Y and Z The Populations of Y nucleus as a function of time is given by Ny t Nox exp 2 1 exp 2 1 Find the time at which N is maximum 2x 2y and determine the populations of X and Z at that instant
The half life of a radioactive nucleus 100 days The time interval h b between t time to when half of it has decayed and the time when three fourth of it had decayed is 1 60 days 2 15 days 3 30 days 4 100 days
Physics
Radioactivity
The half life of a radioactive nucleus 100 days The time interval h b between t time to when half of it has decayed and the time when three fourth of it had decayed is 1 60 days 2 15 days 3 30 days 4 100 days
Determine the factor by which amplitude of an oscillation decreases after 5 cycles whe he period of oscillation changes from 1 500 s to 1 502 s due to application of dampin orce a 0 198 b 0 584 c 0 326 d 0 424
Physics
Radioactivity
Determine the factor by which amplitude of an oscillation decreases after 5 cycles whe he period of oscillation changes from 1 500 s to 1 502 s due to application of dampin orce a 0 198 b 0 584 c 0 326 d 0 424
Two radioactive materials X and X have decay constants 10 and respectively If initially they have the same number of nuclei if the ratio of the number of nuclei of X to that of X will be 1 e 9 after a time Find the value of n n
Physics
Radioactivity
Two radioactive materials X and X have decay constants 10 and respectively If initially they have the same number of nuclei if the ratio of the number of nuclei of X to that of X will be 1 e 9 after a time Find the value of n n
A radioactive sample has a half life of 40 seconds When its activity is measured 80 secon after the begining it is found to be 6 932 x 10 8 dps During this time total energy released 6x 10 joule n2 0 6932 A The initial number of atoms in the sample is 1 6 10 B The initial number of atoms in the sample is 1 6 1021 C Energy released per fission is 5 x 10 13 J D Energy released per fission is 558 10 3 J
Physics
Radioactivity
A radioactive sample has a half life of 40 seconds When its activity is measured 80 secon after the begining it is found to be 6 932 x 10 8 dps During this time total energy released 6x 10 joule n2 0 6932 A The initial number of atoms in the sample is 1 6 10 B The initial number of atoms in the sample is 1 6 1021 C Energy released per fission is 5 x 10 13 J D Energy released per fission is 558 10 3 J
ction E Nuclear Fission and Fusion 92U 235 nucleus absorbs a slow neutron and undergoes fission into 54X139 and 38 Sr94 nuclei The other particles produced in this fission process are A 1 B and 1 a B 2 B and 1 neutron neturons D 3 neutrons combing to form a carbon 120
Physics
Radioactivity
ction E Nuclear Fission and Fusion 92U 235 nucleus absorbs a slow neutron and undergoes fission into 54X139 and 38 Sr94 nuclei The other particles produced in this fission process are A 1 B and 1 a B 2 B and 1 neutron neturons D 3 neutrons combing to form a carbon 120
Velm B M M Two radioactive sources A and B initially contain equal number of radioactive atoms Source A has a half life of 1 hour and source B has a half life of 2 hours At the end of 2 hours the ratio of the rate of disintegration of A to that of B is A 1 2 B 2 1 1 1 T 4 amount initially P and Q of a radioactive substance
Physics
Radioactivity
Velm B M M Two radioactive sources A and B initially contain equal number of radioactive atoms Source A has a half life of 1 hour and source B has a half life of 2 hours At the end of 2 hours the ratio of the rate of disintegration of A to that of B is A 1 2 B 2 1 1 1 T 4 amount initially P and Q of a radioactive substance
It is now believed that protons and neutrons which constitute nuclei of ordinary matter are themselves built out of more elementary units called quarks A proton and a neutron consist of three quarks each Two types of quarks the so called up quark denoted by u of charge 2 3 e and the down quark denoted by d of charge 1 3 e together with electrons build up ordinary matter Quarks of other types have also been found which give rise to different unusual varieties of matter Suggest a possible quark composition of a proton and neutron
Physics
Radioactivity
It is now believed that protons and neutrons which constitute nuclei of ordinary matter are themselves built out of more elementary units called quarks A proton and a neutron consist of three quarks each Two types of quarks the so called up quark denoted by u of charge 2 3 e and the down quark denoted by d of charge 1 3 e together with electrons build up ordinary matter Quarks of other types have also been found which give rise to different unusual varieties of matter Suggest a possible quark composition of a proton and neutron
A photon with an energy of 4 9 eV ejects photoelectrons from tungsten When the ejected electron enters a constant magnetic field of strength B 2 5 mT at an angle of 60 with the field direction the maximum pitch of the helix described by the electron is found to be 2 7 mm Find the work function of the metal in electron volts Given that specific charge of electron is 1 76x10 Ckg wwsex
Physics
Radioactivity
A photon with an energy of 4 9 eV ejects photoelectrons from tungsten When the ejected electron enters a constant magnetic field of strength B 2 5 mT at an angle of 60 with the field direction the maximum pitch of the helix described by the electron is found to be 2 7 mm Find the work function of the metal in electron volts Given that specific charge of electron is 1 76x10 Ckg wwsex