Which of the following statements is not true with respect to photoelectric effect -
1. The plot of kinetic energy of the photoelectrons against frequency of absorbed radiation gives a straight line parallel to x-axis
2. The plot of K.E. of the photoelectrons against frequency of absorbed radiation gives a straight line with slope equal to h and intercept to work function of metal
3. The plot of kinetic energy of the photoelectrons versus the intensity of incident radiation with constant frequency gives a straight line parallel to x-axis
4. When intensity of light is increased the number of photons ejected increases but the energies of these electrons are the same.
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe first line in the Lyman series in the spectrum of hydrogen atom occurs at a wavelength of 1215 Å and the limit for Balmer series is 3645 Å. Calculate the wavelength corresponding to series limit of Lyman series.
1. 911.2 Å
2. 812.2 Å
3. 712.2 Å
4. 678.4 Å
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe correct order of increasing energy of atomic orbital is
1. 3s, 3p, 4s, 3d, 4p
2. 3s, 3p, 3d, 4s, 4p
3. 3s, 3p, 4s, 4p, 3d
4. 3s, 3p, 3d, 4p, 4s
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyIn Rutherford's alpha scattering experiment using gold foil, the kinetic energy of the alpha particle was 1.2 x 10-12J. For a head on collision, using the formula K.E. = x 2Ze2/r0 , what may be the magnitude of r0 [ The nuclear radius of gold, Z=79; = 9 x 109 new-ton/meter2 coulomb-2, e= 1.6x10-19 coulomb]
1. 3 x 10-14m
2. 1.3 x 10-14m
3. 2.1 x 10-14m
4. 4.3 x 10-14m
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe quantum number of the most energetic electron in an Ne atom in the first excited state is
1. 2, 1, 0, +1/2
2. 3, 1, 1, +1/2
3. 3, 0, 0, +1/2
4. 3, 1, 0, +1/2
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe frequency of line spectrum of sodium is 5.09 x 1014 sec-1. Its wavelength (in nm) will be -[C= 3x108m/sec]
1. 510nm
2. 420nm
3. 589nm
4. 622nm
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyThe total number of neutrons in dipositive zinc ions with mass number 70 is -
1. 34
2. 40
3. 36
4. 38
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyWith a certain exciting radiation of a particular frequency, to which hydrogen atoms are exposed, the maximum number of spectral lines obtainable in the emission is 15. The uppermost energy level to which the electron is excited is
1. 4
2. 5
3. 6
4. 7
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyConsider an electron which is brought close to the nucleus of the atom from an infinite distance, the energy of the electron-nucleus system:
1. Increases
2. Decreases
3. Remains the same
4. None of these
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & BiologyWhen accelerated electrons are direct against an anticathode in an X-ray tube, the radiation obtained has a continuous spectrum with a wavelength minimum,
) m, where V is the voltage used for accelerating the electrons.
Calculate min for V= 5 x 104 volts.
1. 1.25 Å
2. 0.75 Å
3. 0.25 Å
4. 1.00 Å
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NEET MCQ Books for XIth & XIIth Physics, Chemistry & Biology