- 1(current)
Q. No.The de Broglie wavelength of an electron in the 4th orbit is:
(where, \( a_0\) = radius of 1st orbit )
1. \(2 \pi a_0\)
2. \(8 \pi a_0\)
3. \(6 \pi a_0\)
4. \(4 \pi a_0\)
1. 1836
2. \(\sqrt{1836}\)
3. \(\frac{1}{1836}\)
4. \(\frac{1}{\sqrt{1836}}\)
1. \(K E_e>K E_p\)
2. \(\mathrm{KE}_{\mathrm{p}}>\mathrm{KE} \mathrm{e}_{\mathrm{e}}\)
3. \(K E_e=K E_p\)
4. \(2 K E_e=K E_p\)
| 1. |  |
2. |  |
| 3. |  |
4. |  |
1. \( \lambda_{\mathrm{p}}<\lambda_{\mathrm{a}}<\lambda_{\mathrm{e}} \)
2. \( \lambda_{\mathrm{p}}<\lambda_{\mathrm{e}}<\lambda_{\mathrm{a}} \)
3. \( \lambda_{\mathrm{a}}<\lambda_{\mathrm{p}}<\lambda_{\mathrm{e}} \)
4. \(\lambda_{\mathrm{a}}<\lambda_{\mathrm{e}}<\lambda_{\mathrm{p}}\)
| 1. | The de Broglie wavelength of an electron is 666.67 nm. |
| 2. | The cathode rays travel from the cathode to the anode. |
| 3. | The characteristics of electrons depend on the metal used in the cathode. |
| 4. | The characteristics of electrons depend on the gas filled inside the cathode tube. |
A proton and a Li3+ nucleus are accelerated by the same potential. If Li3+ and denote the de-Broglie wavelengths of Li3+ and proton respectively, then the value of \(\frac{\lambda _{Li^{3+}}}{\lambda _{p}}\) is x × 10−1. The value of x is:
(Rounded off to the nearest integer)
(Mass of Li3+ = 8.3 the mass of a proton)
1. 4
2. 6
3. 2
4. 8
\(\small{\left[\text { Use }:\sqrt{3}=1.73, \mathrm{~h}=6.63 \times 10^{-34} \mathrm{Js}, \mathrm{~m}_{\mathrm{e}}=9.1 \times 10^{-31} \mathrm{~kg} ;\right.}\)
\(\small{\left.\mathrm{c}=3.0 \times 10^8 \mathrm{~ms}^{-1} ; 1 \mathrm{eV}=1.6 \times 10^{-19} \mathrm{~J}\right]}\)
1. 8.6
2. 6.3
3. 1.4
4. 7.3
A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and m are charge and mass of an electron, respectively, then the value of ( where is the wavelength associated with electron wave) is given by :
1. meV
2. 2meV
3.
4.
The wavelength (in nanometer) associated with a proton moving at 1.0 × 103 ms–1 (Mass of proton = 1.67 × 10–27 kg and h = 6.63 × 10–34 Js) is-:
1. 0.032 nm
2. 0.40 nm
3. 2.50 nm
4. 14.0 nm
- 1(current)
Q. No.
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