جوہری طیف

Written by Dr. Hamza Farooq (Physics)

بارہویں جماعت · طبیعیات · 8 سوالات

نام: ____________________   تاریخ: ____________

1. In the Bohr model, electrons orbit in:

   • A Any orbit
   • B Elliptical only
   • C Straight lines
   • D Fixed energy levels

2. The Lyman series corresponds to transitions ending at:

   • A n = 3
   • B n = 1
   • C n = 4
   • D n = 2

3. X rays are produced when fast electrons:

   • A Are slowed in water only
   • B Hit a metal target
   • C Are reflected by glass
   • D Pass through air

4. LASER stands for light amplification by:

   • A Stimulated emission of radiation
   • B Selective emission of rays
   • C Spontaneous emission of rays
   • D Stimulated electrons

5. The wavelength emitted when an atom jumps between levels depends on:

   • A The energy difference of the levels
   • B The temperature only
   • C Its mass
   • D The atom's colour

6. An atom emits light when an electron:

   • A Stays still
   • B Falls to a lower energy level
   • C Leaves the atom permanently only
   • D Moves to a higher level

7. The energy of the nth level of hydrogen is proportional to:

   • A n
   • B n²
   • C -1 / n²
   • D 1 / n

8. In a laser, the light is:

   • A Only sound
   • B Random and white
   • C Only infrared
   • D Coherent and monochromatic