MCQ
The potential difference between the cathode and the target in a Collidge tube is $100 kV$. The minimum wavelength of the $X-$ rays emitted by the tube is
- A$0.66\ Å$
- B$9.38\ Å$
- C$0.246\ Å$
- ✓$0.123\ Å$
✓
Answer
Correct option: D.
$0.123\ Å$
d
(d) ${\lambda _{\min }} = \frac{{hc}}{{eV}} = \frac{{6.6 \times {{10}^{ - 34}} \times 3 \times {{10}^8}}}{{1.6 \times {{10}^{ - 19}} \times 100 \times {{10}^3}}}$
(d) ${\lambda _{\min }} = \frac{{hc}}{{eV}} = \frac{{6.6 \times {{10}^{ - 34}} \times 3 \times {{10}^8}}}{{1.6 \times {{10}^{ - 19}} \times 100 \times {{10}^3}}}$
$ = 0.123{Å}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Two magnets of same size and mass make respectively 10 and 15 oscillations per minute at certain place. The ratio of their magnetic moments is
Give the $SI$ unit of the magnetic field.
→Which of the following circuits correctly represents the following truth table ?
→$\begin{array}{*{20}{c}}A&B&C\\0&0&0\\0&1&0\\1&0&1\\1&1&0\end{array}$
A radioactive nucleus with Z protons and N neutrons emits an a-particle, 2b-particles and 2 gamma rays. The number of protons and neutrons in the nucleus left after the decay respectively, are
One turn of insulated wire in the form of a planar square frame with side $l = 0.2\,m$ and resistance $1\,\Omega $ is placed in a uniform magnetic field perpendicular to the magnetic field lines. The current passing through the turn when magnetic field starts to decrease at a constant rate of $0.1\,T/ s$ is....$mA$
→In which of the following the final image is erect?
There are two coils A and B as shown in the figure. A current starts flowing in B as shown, when A is moved towards B and stops when A stops moving. The current in A is counter clockwise. B is kept stationary when A moves. We can infer that
A 4 μF condenser is connected in parallel to another condenser of 8 μF. Both the condensers are then connected in series with a 12 μF condenser and charged to 20 volts. The charge on the plate of 4 μF condenser is
Half life of $B{i^{210}}$ is $5$ days. If we start with $50,000$ atoms of this isotope, the number of atoms left over after $10$ days is
→A person who can see things most clearly at a distance of $10\, cm$. Requires spectacles to enable to him to see clearly things at a distance of $30 \,cm$. What should be the focal length of the spectacles
→