enEnglishhiहिन्दी
JEE Mains · Physics · STD 12 - Dual nature of radiation and matter
- JEE Mains 2022
- Hard
- MCQ
The electric field at the point associated with a light wave is given by \(E=200\left[\sin \left(6 \times 10^{15}\right) t+\sin \left(9 \times 10^{15}\right) t\right] \,Vm ^{-1}\) Given : \(h=4.14 \times 10^{-15} \,eVs\) If this light falls on a metal surface having a work function of \(2.50 \,eV\), the maximum kinetic energy of the photoelectrons will be ........... \(eV\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(3.42\)
Step-by-step Solution
Detailed explanation
For maximum \(KE\) we will take higher frequency \(\left(f=\frac{9 \times 10^{15}}{2 \pi} Hz \right)\)
\(K_{\max }=h f-\phi\)
\(=\frac{9 \times 10^{15} \times 4.14 \times 10^{-15}}{2 \pi}-2.50\)
\(3.43 \,eV\)
nearest is \(3.42 \,eV\)
More questions from Physics
- A body of mass \(2\, kg\) moves under a force of \((2 \hat{ i }+3 \hat{ j }+5 \hat{ k }) \,N\). It starts from rest and was at the origin initially. After \(4 \,s\), its new coordinates are \((8, b, 20)\). The value of \(b\) is ........ . (Round off to the Nearest Integer)JEE Mains 2021 Medium
- In a certain thermodynamical process, the pressure of a gas depends on its volume as \(kV ^{3}\). The work done when the temperature changes from \(100^{\circ} C\) to \(300^{\circ} C\) will be .......... \(nR\), where \(n\) denotes number of moles of a gas.JEE Mains 2021 Hard
- The minimum energy required by a hydrogen atom in ground state to emit radiation in Balmer series is nearly _______.JEE Mains 2024 Hard
- A hoop of radius \(r\) and mass \(m\) rotating with an angular velocity \(\omega_0\) is placed on a rough horizontal surface. The initial velocity of the centre of the hoop is zero. What will be the velocity of the centre of the hoop when it ceases to slip?JEE Mains 2013 Medium
- A body of mass \(200\,g\) is tied to a spring of spring constant \(12.5\,N / m\), while the other end of spring is fixed at point \(O\). If the body moves about \(O\) in a circular path on a smooth horizontal surface with constant angular speed \(5\,rad / s\), then the ratio of extension in the spring to its natural length will be :JEE Mains 2023 Hard
- A bob of mass \(m\) attached to an inextensible string of length \(l\) is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed \(\omega\ rad/s\) about the vertical. About the point of suspension:JEE Mains 2014 Easy
More PYQs from JEE Mains
- Assuming the earth to be a sphere of uniform mass density, the weight of a body at a depth \(d=\frac{R}{2}\) from the surface of earth, if its werght on the surface of earth is \(200\,N\), will be \(...........\,N\) ( \(Given R =\) Radrus of earth)JEE Mains 2023 Medium
- Work done by a Carnot engine operating between temperatures \(127^{\circ}\,C\) and \(27^{\circ}\,C\) is \(2\,kJ\). The amount of heat transferred to the engine by the reservoir is \(........\,kJ\)JEE Mains 2023 Medium
- A horizontal straight wire \(5 \mathrm{~m}\) long extending from east to west falling freely at right angle to horizontal component of earth's magnetic field \(0.60 \times 10^{-4} \ \mathrm{Wbm}^{-2}\). The instantaneous value of emf induced in the wire when its velocity is \(10 \mathrm{~ms}^{-1}\) is _______ \(\times 10^{-3} \mathrm{~V}\)JEE Mains 2024 Hard
- The electric field of an electromagnetic wave in free space is \(\overrightarrow{\mathrm{E}}=57 \cos \left[7.5 \times 10^6 \mathrm{t}-5 \times 10^{-3}(3 x+4 y)\right](4 \hat{i}-3 \hat{j}) N / C\). The associated magnetic field in Tesla is _______.JEE Mains 2025 Medium
- For an ideal gas the instantaneous change in pressure \('{p} '\) with volume \('v'\) is given by the equation \(\frac{{dp}}{{dv}}=-{ap} .\) If \({p}={p}_{0}\) at \({v}=0\) is the given boundary condition, then the maximum temperature one mole of gas can attain is : (Here \({R}\) is the gas constant)JEE Mains 2021 Hard