X-Rays Questions and Answers

K and KX rays are emitted when there is a transition of electron between the levels O O O n 2 to n 1 and n 3 to n 1 respectively n 2 to n 1 and n 3 to n 2 respectively n 3 to n 2 and n 4 to n 2 respectively

Q 10 Moderate 4 00 23 O Consider the following two statements A and Band identify the correct choice in the given answer 400 A The characteristic X ray spectrum depends on the nature of the material of the target B The short wavelength limit of continuous X ray spectrum varies inversely with the potential difference

Define the thickness of the air shield needed to reduce the intensity of monochromatic y radiation with the photon energy of 200 keV by a factor of 10 The linear attenuation coefficient for air at 200 keV is 0 016 m 1 Select one O 6 9 km O 20m O 53 m O 145 m

Based on latest C B S E T S C syllabus and guidelines Provides Complete solution to N C E R T In Text Questions Exercises N C E R T Exemplar Problems fully solved Includes Value Based Questions Includes H O T S Questions and Problems Objective Questions Bank covers latest Questions from N E E T J E E Main J E E Advanced and other Competitive Examinations S K Malhotra Specimen Copy Not for Sale X Vol

6 A A Si diode dissipates 2 5W for a forward current of 1 5A Determine the forward voltage drop across the diode and its bulk resistance B Determine VDI VD2 and Vo for the circuit shown 2 3 Si E Si VD1 10 V Voz R ww 3 9 KM Vo

VS Transfer characteristics output voltage input voltage V for a base biased transistor in CE configuration is as shown in the figure For using transistor as a switch it is used Vo NII III 1 in region II 2 in region I 3 in region III 4 both in region 1 II Vi

The wavelengths of K X rays for lead isotopes P Pb 206 are and respectively Then b in i in and Pb204 2 c h d A iz AIIMS 12 The shortest wavelength of X rays coming from

Which one of the following statements is WRONG in the context of X rays generated from a X ray tube A Wavelength of characteristic X rays decreases when the atomic number of the target increases B Cut off wavelength of the continuous X rays depends on the atomic number of the target C Intensity of the characteristic X rays depends on the electrical power given to the X ray tube D Cut off wavelength of the continuous X rays depends on the energy of the electrons in the X ray tube

4 Transfer characteristics output voltage Vo vs input voltage V for a base biased transistor in CE configuration is as shown in the figure For using transistor as a switch it is used 2012 II III N Vo a in region III b both in region I and III c in region II d in region I V

A p n photodiode is made of a material with a band gap of 2 0 eV The minimum frequency of the radiation that can be absorbed by the material is nearly a 10 10 4 Hz c 1 10 4 Hz The circuit 2008 b 5 10 4 Hz d 20 10 4 Hz 2008

A cobalt target is bombarded with electrons and a characteristic x ray spectrum is measured A second fainter characteristic spectrum is observed due to impurity in cobalt The wavelengths of the Ka lines are 178 9 pm cobalt and 143 5 pm impurity and the proton number for cobalt is 27 Determine the impurity element using only these data 3

Manufacturers of wire and other objects of small dimension sometimes use a laser to continually monitor the thickness of the product The wire intercepts the laser beam producing a diffraction pattern like that of a single slit of the same width as the wire diameter Fig 36 37 Suppose a helium neon laser of wavelength 632 8nm illuminates a wire and the diffraction pattern appears on a screen at distance L 2 60m If the desired wire diameter is 1 37mm what is the observed distance between the two tenth order minima one on each side of the central maximum Wire He Ne laser Figure 36 37 Problem 10 Wire making machine

2 When a free neutron decays to form a proton and an electron then choose the incorrect statement 1 The relation may be expressed as n p e v 2 Every electron comes out with the same energy 3 The electron shares the major part of the energy released 4 All the above 3 Photons of energy 6 eV are incident on a metal surface whose work function is 4 eV The minimum

In a p n Junction Diode a square input signal of 10V is applied as shown in the figure 5V HI R SV Then the output signal across R will be skipped B 5V n 10 V n QU MY F S

Electrostatic experiments do not work well on humid days because moist air conducts electricity A charged matellic body has same potential but the distribution of charge may or may not be uniform A small metal ball is suspended in a uniform electric field with the help of an insulated thread If a high ener X ray beam falls on the ball it will be deflected in the direction of the field

of How much energy will be released when 10 kg of U235 is completely converts into energy 1 5 x 1027 MeV 2 5 x 1024 MeV 3 9 x 1017 J 4 All of these much energy is released when 2 mole of U235

When the voltage applied to an X ray tube increased from V 15 5 KV to V 31 KV the wavelength interval between the Ka line and the short wavelength cut off of the continuous X ray spectrum increases by a factor of 1 3 Find the atomic number of the element of the target If your N answer is N fill value of Take hc 13 1240 eV nm and R 1 107m

5 Characteristic X rays are not obtained in the spectrum of H atom because 1 hydrogen is a gas 2 hydrogen is very light 3 energy difference in energy levels of hydrogen is much less 4 energy difference in energy levels of hydrogen is much high 1947

Ge and Si diodes conduct at 0 3 V and 0 7 V respectively In the following figure if Ge diode connection is reversed the value of V changes by 12VI 1 0 2 V Ge A Si 5k2 Vo 11 2 0 4 V

0 A small metallic ball is suspended in a uniform electric field with the help of an insulated thread If high energy X ray beam falls on the ball the ball will be deflected in the direction of the field 1983

1 The momentum a 13 26x10 26 of an X ray photon with 0 5 is kg m s b 1 326x10 26 kg m s kg m s c 13 26x10 24 d 13 26 x 10 22 kg m s

The wavelength of Ka X ray produced by a X ray tube is 0 76 The atomic number of the anode material of the tube is A 38 C 63 B 40 D 53

ALLEM reduce the ripples in a rectifier circuit with 13 capacitor filter a R should be increased b Input frequency should be decreased c Input frequency should be increased d Capacitors with high capacitance should be used 1 Only a 3 a b and d 2 Only a and b 4 a c and d The energy of radiation emitted by LED is 1 greater than the band gap of the semiconductor used 2 always less than the band gap of the semiconductor used 3 always equal to the band gap of the semiconductor used 4 equal to or less than the band gap of the semiconductor used In a common emitter transistor circuit the bas than V is

13 50 of the X ray coming from a Coolidge tube is able to pass through a 0 1 mm thick aluminium foil If the potential difference between the target and the filament is increased the fraction of the X ray passing through the same foil will be A 0 C 50 B 50 D 50

Which of the following statements is are regarding X ray tube 1 Continuous X rays are produced due to transition of an electron from higher energy levels to vacant lower energy level 2 The shortest wavelength produced in an X ray tube dependent only on the target material 3 On increasing potential difference between the filament and target frequency of continuous X rays increases ALL

Output Y of the given logic gate network is A Bo 1 A B A B 2 A B A B 3 A B A B y

ged id Yellow light is used in single slit diffraction Xa experiment with slit width 0 6 mm If yellow light is replaced by X rays then the pattern will reveal 1 That the central maxima is narrower 2 No diffraction pattern 3 More number of fringes 4 Less number of fringes Huygen s conception of secondary wayes 2

20 An n p n transistor circuit is arranged as shown in the figure It is a common 1 Base amplifier circuit 2 Emitter amplifier circuit 3 Collector amplifier circuit 4 None of these NPN www R out

Which of the following statements about electromagnetic waves is are correct 1 X rays in vacuum travel faster than light waves in vacuum 2 The energy of X ray photon is greater than that of a light photon 3 Light can be polarised but X ray cannot 1 1 and 2 2 2 and 3 3 1 2 and 3 T 001 nolisups on 4 2 only

The conductivity of semiconductor increases with increase in temperature because A both number density of charge carriers and relaxation time increase B number density of charge carriers increases C number density of current carriers increases relaxation time decreases but effect of decrease in relaxation time is much less than increase in number density relaxation time inor D Ga

The wavelength of the characteristics X ray k line emitted from zinc Z 30 is 1 415A Find the wavelength of the k line emitted from molybdenum Z 42 1 2 83 3 0 538 2 0 708 4 0 621

A silicon specimen is made into a p type semiconductor by doping on an average one indium atom p 5 x 107 silicon atoms If the number density of atoms in the silicon specimen is 5 x 1028 atm m then th number of acceptor atoms in silicon per cubic centimeter will be 1 2 5 1030 2 2 5 1035 3 1 0 1013 4 1 0 1015

22 For a tungsten target the K line wavele a more than K approximately percentage 1 15 6 3 12 9 line wavelength by 2 18 5 4 11 9 23 A y ray source shows a count rate of 320 per second when placed before a geiger counter If the half life of the source nuclei is 30 minutes then after 2 hours the count rate per second will be 1 25 3 20 2 30 4 35

16 An incident beam of X rays of wavelength 100 pm is incident on a carbon target The scattered radiation is viewed at 90 to the incident beam and it is observed that the scattered beam has a wavelength of 97 57 pm If the scattered radiation is viewed at 60 to the incident beam the wavelength of the scattered beam will be close to 1 98 78 pm 3 97 82 pm 2 96 75 pm 4 96 46 pm de Broglie

Example 6 Calculate the least and maximum values of wavelength obtained whe Y rays of energy 0 5 MeV are scattered by matter Solution Wavelength of incident photons

An experiment is performed to determine the I V characteristics of a Zener diode which has a protective resistanc R 10092 and a maximum power of dissipation rating of 1 W The minimum voltage range of the DC source in circuit is A 0 5V B 0 24V C 0 12V D 0 8V

For a transistor amplifier the voltage gain A is low at high high and low frequencies and constant at mid frequencies B remains frequencies constant for all C constant at high frequencies and low at low frequencies low D is high at high and frequencies and constant in the middle frequency range

56 In p n junction photocell electromotive force due to monochromatic light is proportional to 1 p n potential barrier 2 intensity of light 3 frequency of light 4 p n applied voltage Am 01 1

voltage V is circuit shown in figure the maximum output 10 V Avi T 2 0 1 0 V 3 10 V D 2kQ 2 5 V 2kS2 ww 5 4 Vo V D 2 2kQ

in an n p n transistor 10 0 electrons enter the emitter in 10 s 2 of the electrons are lost in the base Calculate the current amplification factor B M

We X ray a broken foot of mass 1 4 kg The total X ray dose is 1 1 millirads 0 011 milligray If the X ray has energy of 10 keV how many X ray photons were absorbed 9 375 x 10 12

We X ray a broken foot of mass 1 3 kg The total X ray dose is 1 1 millirads 0 011 milligray If the X ray has energy of 10 keV how many X ray photons were absorbed

Though we cannot see X rays a we can use them to help plants grow b we can feel them on our skin c we can use them to take photos of distant galaxies d we can use them as communication devices

Which statement is true regarding single-slit interference? The dark fringes are all equally spaced. All bright fringes have the same intensity. There is a dark fringe at the centre. The central maximum is twice as wide as the other maxima.

How many transcontinental flights would a person have to take in a year to raise the annual radiation dosage to 0.2 Sv?

Data Below are the opening sentences from the Republican and Democratic Platforms in 1968. Opening to the Republican Platform, 1968: A century ago, Abraham Lincoln gave that leadership. From it came one nation, consecrated to liberty and justice for all. Fifteen years ago, Dwight D. Eisenhower gave that leadership. brought the end of a war, eight years of peace, enhanced respect in the world, orderly progress at home, and trust of our people in their leaders and in themselves. Today, we are in turmoil. Tens of thousands of young men have died or been wounded in Vietnam. Many young people are losing faith in our society. Our inner cities have become centers of despair. Opening to the Democratic Platform, 1968: In America and in the world over, strong forces for change are on the move. Systems of thought have been jarred, ways of life have been uprooted, institutions are under siege. The governed challenge those who govern. We are summoned, therefore, to a fateful task-to ensure that the turmoil of change will prove to be the turmoil of birth instead of decay. We cannot stand still until we are overtaken by events. We dare not entrust our lives to the blind play of accident and force. By reflection and choice, we must make the impulse for change the agent of orderly progress. Part B What did you notice about the differences in the two opening statements? What appeals to voters did you read in the Republican statement? Who do you think the Democrats were trying to appeal to?