Question
In producing X-rays a beam of electrons accelerated by a potential difference V is made to strike a metal target. For what value of V, X-rays will have the lowest wavelength of 0.3094 Å
| (a) 10 kV | (b) 20 kV | (c) 30 kV | (d) 40 kV |
In producing X-rays a beam of electrons accelerated by a potential difference V is made to strike a metal target. For what value of V, X-rays will have the lowest wavelength of 0.3094 Å
| (a) 10 kV | (b) 20 kV | (c) 30 kV | (d) 40 kV |
(d) 40 kV
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An electron is travelling in east direction and a magnetic field is applied in upward direction then electron will deflect in
|
(a) South |
(b) North |
(c) West |
(d) East |
Light of wavelength 1824 Å, incident on the surface of a metal, produces photo-electrons with maximum energy 5.3 eV. When light of wavelength 1216 Å is used, the maximum energy of photoelectrons is 8.7 eV. The work function of the metal surface is
|
(a) 3.5 eV |
(b) 13.6 eV |
(c) 6.8 eV |
(d) 1.5 eV |
Which of the following statements are true regarding Bohr's model of hydrogen atom
(I) Orbiting speed of electron decreases as it shifts to discrete orbits away from the nucleus
(II) Radii of allowed orbits of electron are proportional to the principal quantum number
(III) Frequency with which electrons orbits around the nucleus in discrete orbits is inversely proportional to the principal quantum number
(IV) Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits Select correct answer using the codes given below
Codes :
|
(a) I and III |
(b) II and IV |
(c) I, II and III |
(d) II, III and IV |
The line joining the pole and the centre of curvature of a mirror is called the: