JEE Mains · Chemistry · STD 11 - 2. structure of atom
A stream of electrons from a heated filaments was passed 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 \(h/\lambda ,\) (where \(\lambda\) is wavelength associated with electron wave) is given by :
- A \(\sqrt {meV}\)
- B \(\sqrt {2meV}\)
- C \(meV\)
- D \(2meV\)
Answer & Solution
Correct Answer
(B) \(\sqrt {2meV}\)
Step-by-step Solution
Detailed explanation
Kinetic energy \(=e V=\frac{1}{2} m u^{2}\) \(u=\sqrt{\frac{2 e V}{m}}\) Here, u is the velocity of the electron. The de broglie wavelength is \(\lambda=\frac{h}{m u}\) \(\frac{h}{\lambda}=m u\) Substitute equation (1) in equation (2)…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- The reaction \(2N_2O_5\,(g) \to 4NO_2\,(g) + O_2\,(g)\) follows first order kinetics. The pressure of a vessel containing only \(N_2O_5\) was found to increase from \(50\,mmHg\) to \(87 .5\,mmHg\) in \(30\,min.\) The pressure exerted by the gases after \(60\,min.\) will be .......... \(mmHg\) (assume temperature remains constant)JEE Mains 2015 Hard
- The number of \(sp^2\) hybrid orbitals in a molecule of benzene isJEE Mains 2020 Hard
- If a reaction follows the Arrhenius equation, the plot \(\ln k\) vs \(1/(RT)\) gives straight line with a gradient \((-y)\) \(unit\). The energy required to activate the reactant isJEE Mains 2019 Medium
- Given below are two statements :
Statement I : A homolepitc octahedral complex, formed using monodentate ligands, will not show stereoisomerism.
Statement II : cis- and trans- platin are heteroleptic complexes of Pd.
In the light of the above statements, choose the correct answer from the options given below.JEE Mains 2025 Medium - Which of the following statement is true with respect to \(\mathrm{H}_2 \mathrm{O}, \mathrm{NH}_3\) and \(\mathrm{CH}_4\) ?
A. The central atoms of all the molecules are \(\mathrm{sp}^3\) hybridized.
B. The \(\mathrm{H}-\mathrm{O}-\mathrm{H}, \mathrm{H}-\mathrm{N}-\mathrm{H}\) and \(\mathrm{H}-\mathrm{C}-\mathrm{H}\) angles in the above molecules are \(104.5^{\circ}, 107.5^{\circ}\) and \(109.5^{\circ}\), respectively.
C. The increasing order of dipole moment is \(\mathrm{CH}_4 \lt \mathrm{NH}_3 \lt \mathrm{H}_2 \mathrm{O}\).
D. Both \(\mathrm{H}_2 \mathrm{O}\) and \(\mathrm{NH}_3\) are Lewis acids and \(\mathrm{CH}_4\) is a Lewis base.
E. A solution of \(\mathrm{NH}_3\) in \(\mathrm{H}_2 \mathrm{O}\) is basic. In this solution \(\mathrm{NH}_3\) and \(\mathrm{H}_2 \mathrm{O}\) act as Lowry-Bronsted acid and base respectively.
Choose the correct answer from the options given below:JEE Mains 2025 Medium - The major product \([B]\) in the following sequence of reactions is \(\begin{array}{*{20}{c}}
{C{H_3} - C = CH - C{H_2}C{H_3}} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{CH{{(C{H_3})}_2}\,\,\,\,\,\,\,\,\,\,}
\end{array}\xrightarrow[{(ii)\,{H_2}{O_2},O{H^ - }}]{{(i)\,{B_2}{H_6}}}[A]\)\(\xrightarrow[\Delta ]{{dil.\,{H_2}S{O_4}}}[B]\)JEE Mains 2020 Hard
More PYQs from JEE Mains
- Normal of the curve \({x^2} + 2xy - 3{y^2} = 0\) at point \((1,1)\) intersect curve again at which quadrantJEE Mains 2015 Hard
- 40 mL of a mixture of \(\mathrm{CH}_3 \mathrm{COOH}\) and HCl (aqueous solution) is titrated against 0.1 M NaOH solution conductometrically. Which of the following statement is correct?
JEE Mains 2025 Hard - The series of positive multiples of \(3\) is divided into sets : \(\{3\},\{6,9,12\},\{15,18,21,24,27\}, \ldots\) Then the sum of the elements in the \(11^{\text {th }}\) set is equal to \(................\)JEE Mains 2022 Hard
- Let \(f(x)=x-1\) and \(g(x)=e^x\) for \(x \in \mathbb{R}\). If \(\frac{d y}{d x}=\left(e^{-2 \sqrt{x}} g(f(f(x)))-\frac{y}{\sqrt{x}}\right), y(0)=0\), then \(y(1)\) is :-JEE Mains 2025 Medium
- Assertion : Nitrogen and oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen. Reason : The reaction between nitrogen and oxygen requires high temperature.JEE Mains 2015 Medium
- A point on the ellipse, \(4x^2 + 9y^2 = 36\), where the normal is parallel to the line, \(4x -2y-5 = 0\) , isJEE Mains 2013 Hard