| 1 |
When meta I is heated sufficiently electrons are given off by the metal. This phenomenon is known as. |
- A. Photoelectric effect
- B. Piezo electric effect
- C. Thermionic emission
- D. Secondary emission
|
| 2 |
When an electron in an atom goes from a lower to higher orbit its: |
- A. K.E increases , P.E decreases
- B. K.E increases , P.E increases
- C. K.E decreases , P.E increases
- D. K.E decreases , P.E decreases
|
| 3 |
Earth orbital speed is |
- A. 10 km/s
- B. 20 km/s
- C. 30 km/s
- D. 40 km/s
|
| 4 |
The 1<sup>st</sup> Bohr atom in the hydrogen atom has radius |
- A. 3.56 x 10<sup>-10</sup> m
- B. 0.053 x 10<sup>-11</sup> m
- C. 0.53 x 10<sup>-11</sup> m
- D. 5.30 x 10<sup>-11</sup> m
|
| 5 |
First spectral series of hydrogen atom was discovered by |
- A. Lyman
- B. Rydberg
- C. Balmer
- D. Paschen
|
| 6 |
Frequency of x-rays depends upon. |
- A. Number of electrons striking target
- B. Accelerating potencial
- C. Nature of the target
- D. Both B and C
|
| 7 |
The unit of Rh is. |
- A. ms-1
- B. m
- C. m<sup>2</sup>
- D. m<sup>-1</sup>
|
| 8 |
Balmer series lies in region of electromagnetic spectrum. |
- A. Infrared
- B. Visible
- C. Ultraviolet
- D. Fra infrared
|
| 9 |
The shortest wave length is Bracket series has wave length. |
- A. 16/Rn
- B. Rn/16
- C. 16 Rn
- D. 4 Rn
|
| 10 |
The X-rays diffraction with crystal was first studied by |
- A. W.H Bragg
- B. W.L. Bragg
- C. Michelson
- D. None of these
|
