331. Total number of series in hydrogen spectrum is_____________?
A. three
B. four
C. five
D. six

332. The radiations emitted form hydrogen filled discharge tube show____________?
A. band spectrum
B. line spectrum
C. continuous spectrum
D. absorption spectrum

333. Photon of highest frequency will be absorbed when transition takes place from_____________?
A. 1st to 5th orbit
B. 2nd to 5th orbit
C. 3rd to 5th orbit
D. 4th to 5th orbit

334. In obtaining an X-ray photograph of our hand we use the principle of______________?
A. photo electric effect
B. ionization
C. shadow photograph
D. any of above

335. When we excite some atoms by heat collision or electrical discharge they will________________?
A. radiate electromagnetic energy with a continuous distribution of wavelength
B. absorb particular wavelengths when white light is incident on them
C. radiate electromagnetic energy of discrete characteristic wavelength
D. emit either invisible or visible light

336. Which one of following postulate is in accordance with the Rutherfords model ?
A. continuous spectra for atoms
B. discrete spectra for atoms
C. either continuous nor discrete
D. no spectrum

337. Ground state energy of the 4th orbit in a H-atom is_____________?
A. 13.60 eV
B. 3.40 eV
C. 0.85 eV
D. 1.51 eV

338. The electric P.E of an electron in an orbit at a distance rn from the positive charge_____________?
A. Ke2/rn
B. Ke2/rn2
C. ÀKe2/rn
D. ÀKe2/rn2

339. Bracket series is obtained when all transition of electron terminate on_______________?
A. 4th orbit
B. 5th orbit
C. 3rd orbit
D. 2nd orbit

340. The penetrating power of X-rays depends on their______________?
A. applied voltage
B. frequency
C. source
D. all of the above

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