| 1.) Nernst glower is used to produce | |
| A) | U-V-rays |
| B) | Microwaves |
| C) | Radio waves |
| D) | Far I.R rays |
| 2.) Radius of 3rd bohr orbit is | |
| A) | o‘>6.259Ao |
| B) | o‘>2.116Ao |
| C) | o‘>4.761Ao |
| D) | o‘>8.464Ao |
| 3.) The nuclues of tritium consists of | |
| A) | 1 proton + 1 meutron |
| B) | 1 proton + 3 neutrons |
| C) | 1 proton + 0 neutons |
| D) | 1 proton + 2 neutrons |
| 4.) The elctronic state in which the hydrogen atom can absorb a photon but cannot emit a photon is | |
| A) | 2p |
| B) | 3s |
| C) | 1s |
| D) | 4p |
| 5.) Energy value which is equal to mass of one electron is—- ergs | |
| A) | -7‘>8.2×10-7 |
| B) | -8‘>9.2×10-8 |
| C) | -10‘>8.2×10-10 |
| D) | -8‘>4.1×10-8 |
| 6.) The source of ultraviolet radiations is | |
| A) | Nernst glower |
| B) | oC’>Silicon carbide heated to 1500oC |
| C) | High pressure hydrogen discharge tube |
| D) | Tugsten filament bulb |
| 7.) The charge of an electron is 1.6 x 10-19 coulombs. What will be the value of charge om Na+ ion | |
| A) | -19 C’>1.6×10-19 C |
| B) | -19 C’>3.2×10-19 C |
| C) | -19 C’>2.4×10-19 C |
| D) | -19 C’>11×1.6×10-19 C |
| 8.) The metal best used in photoelectric cells is | |
| A) | Na |
| B) | Mg |
| C) | Al |
| D) | Cs |
| 9.) Line spectrum is charecteristic of | |
| A) | Atoms |
| B) | Molecules |
| C) | Any substance in solid state |
| D) | Any substance in liquid state` |
| 10.) If the velocity of an electron in the second orbit of hydrogen atom is x, the velocity in fourth orbit will be | |
| A) | x/16 |
| B) | 16x |
| C) | x/4 |
| D) | x/2 |
| 11.) The value of rydberg constant is | |
| A) | -1‘>109677 cm-1 |
| B) | -1 s-1‘>109700 cm-1 s-1 |
| C) | -1‘>10968 cm-1 |
| D) | 10970 m |
| 12.) An oxide of nitrogen has a molecular weight of 30. Total number of electrons in one molecule of the compound is | |
| A) | 15 |
| B) | 30 |
| C) | 45 |
| D) | 60 |
| 13.) Which of the following is not a fundamental particle? | |
| A) | Proton |
| B) | Neutron |
| C) | Alpha particle |
| D) | Electron |
| 14.) The frequency associated with photon of radiation having a wavelength of 6000A0 is/ | |
| A) | 14 Hz’>5×1014 Hz |
| B) | 10 Hz’>5×1010 Hz |
| C) | 14 Hz’>2×1014 Hz |
| D) | 15 Hz’>5×1015 Hz |
| 15.) Which of the following is not an electromagnetic radiation? | |
| A) | Gamma rays |
| B) | Alpha rays |
| C) | Radio waves |
| D) | X-rays |
| 16.) The isotopes of neutral atoms of an element differ in | |
| A) | Atomic numbers |
| B) | Mass number |
| C) | Number of electrons |
| D) | Chemical properties |
| 17.) The value of e/m for an electron is? | |
| A) | 8 c/g’>1.78 X 108 c/g |
| B) | -24 c/g’>1.6724 X 10-24 c/g |
| C) | 0.005486 c/g |
| D) | 1.00866 c/g |
| 18.) The number of neutrons present in the radioactive isotope of hydrogen is? | |
| A) | 0 |
| B) | 1 |
| C) | 2 |
| D) | 3 |
| 19.) The first use of quantum theory to explain the structure of atom was made by | |
| A) | Planck |
| B) | Einstein |
| C) | Bohr |
| D) | Heiseberg |
| 20.) The spectrum obtained from incandescent solids is | |
| A) | Continuous |
| B) | Line |
| C) | Band |
| D) | None of these |
| 21.) The radiation with highest wave number | |
| A) | Microwaves |
| B) | X-rays |
| C) | I.R_rays |
| D) | Radiowaves |
| 22.) The radius of the first orbit of hydrogen is 0.53Ao. The radius of second orbit of He+ would be | |
| A) | o‘>0.265Ao |
| B) | |
| C) | o‘>2.12Ao |
| D) | o‘>0.53Ao |
| 23.) The modern atomic mass unit is based on the mass of | |
| A) | 12‘>C12 |
| B) | 14‘>C14 |
| C) | 1‘>H1 |
| D) | 14‘>N14 |
| 24.) The mass of one mole of electron is | |
| A) | 1.008g |
| B) | 0.55mg |
| C) | 0.184mg |
| D) | 1.673 mg |
| 25.) The ratio of the radii of the first three orbits in an atom of hydrogen is | |
| A) | 1:4:9 |
| B) | 9:4:1 |
| C) | 1:2:3 |
| D) | 3:2:1 |
Saturday, November 8, 2008
atomic structure
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