Download App

Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsDual Nature of Radiation and Matter3 Marks
Question
  1. Using de Broglie's hypothesis, explain with the help of a suitable diagram, Bohr's second postulate of quantization of energy levels in a hydrogen atom.
  2. The ground state energy of hydrogen atom is - 13.6 eV. What are the kinetic and potential energies of the electron in this state?
✓

Answer

  1. $\lambda = \frac{\text{h}}{\text{p}} = \frac{\text{h}}{\text{mv}}$


$2\pi\text{r} = \text{n}\lambda$

$ =\text{n}\frac{\text{h}}{\text{mv}}$

$\Rightarrow\text{mvr} = \text{L} = \frac{\text{nh}}{2\pi}$
  1. Kinetic energy=13.6 eV
Potential energy = -27.2 eV.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Dual Nature of Radiation and Matter→Dual Nature of Radiation and Matter — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

An inductor 200mH, a capacitor $100\mu\text{F}$ and a resistor $10\Omega$ are connected in series to an a.c. source of 100V, having variable frequency.
  1. At what frequency of the applied voltage will the power factor of the circuit be 1?
  2. What will be the current amplitude at this frequency?
  3. Calculate the Q-factor of the circuit.
→
What is electric flux? Write its S.I. units.Using Gauss’s theorem, deduce an expression for the electric field at a point due to a uniformly charged infinite plane sheet.
→
State two important properties of photon which are used to write Einstein's photoelectric equation. Define (i) Stopping potential and (ii) Threshold frequency, using Einstein's equation and drawing necessary plot between relevant quantities.
→
Two blocks each having a mass of 3.2kg are connected by a wire CD and the system is suspended from the ceiling by another wire AB figure, The linear mass delity of the wire AB is 10g/m and that of CD is 8g/m. Find the speed of a transverse wave pulse produced in AB and in CD.
→
A long, straight wire of radius r carries a current i and is placed horizontally in a uniform magnetic field B pointing vertically upward. The current is uniformly distributed over its cross-section.
  1. At what points will the resultant magnetic field have maximum magnitude? What will be the maximum magnitude?
  2. What will be the minimum magnitude of the resultant magnetic field?
→
A potentiometer wire of length 1 m has a resistance of 10$\Omega$. It is connected to a 6 V battery in series with a resistance of 5$\Omega$. Determine the emf of the primary cell which gives a balance point at 40 cm.
→
Name the parts of the electromagnetic spectrum which is:
  1. Suitable for radar systems used in aircraft navigation.
  2. Used to treat muscular strain.
  3. Used as a diagnostic tool in medicine.
Write in brief, how these waves can be produced.
→
Define the terms (i) 'cut-off voltage' and (ii) 'threshold frequency' in relation to the phenomenon of photoelectric effect.
Using Einstein's photoelectric equation show how the cut-off voltage and threshold frequency for a given photosensitive material can be determined with the help of a suitable plot/graph.
→
Define mutual inductance between a pair of coils. Derive an expression for the mutual inductance of two long coaxial solenoids of the same length wound one over the other.
→
A vector $\overrightarrow{\text{A}}$ makes an angle of 20° and $\overrightarrow{\text{B}}$ makes an angle of 110° with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the resultant.
→