Moving Charges and Magnetism — Physics STD 12 Science — Question

Kirchhoff ’s junction rule is a reflection of:

The energy of an atom (or ion) in its ground state is -54.4eV. It may be:

1. Hydrogen.
2. Deuterium.
3. He⁺
4. Li⁺⁺

Which one is reverse-biased

(a)

(b)

(c)

(d)

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

Which of the following in a hydrogen atom is independent of the principal quantum number n? (The symbols have their usual meanings).

Hydrogen atom emits blue light when it changes from n = 4 energy level to the n = 2 level. Which colour of light would the atom emit when it changes from the n = 5 level to the n = 2 level

(a) Red

(b) Yellow

(c) Green

(d) Violet

When light falls on matter, it can produce:

Which of the following is not a correct statement

(a) The wavelength of red light is greater than the wavelength of green light

(b) The wavelength of blue light is smaller than the wavelength of orange light

(c) The frequency of green light is greater than the frequency of blue light

(d) The frequency of violet light is greater than the frequency of blue light

Statement-I : Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion and

Statement-II: For heavy nuclei, binding energy per nucleon increases with increasing Z. while for light nuclei it decreases with increasing Z.