Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 17: Problem 2385

In photo electric effect, if threshold wave length of a metal is \(5000 \AA\) work function of this metal is ..........V. $\left(\mathrm{h}=6.62 \times 10^{-34} \mathrm{~J} . \mathrm{s}, \mathrm{c}=3 \times 10^{8} \mathrm{~m} / \mathrm{s}, 1 \mathrm{eV}=1.6 \times 10^{-19} \mathrm{~J}\right)$ (A) \(1.24\) (B) \(2.48\) (C) \(4.96\) (D) \(3.72\)

Short Answer

Expert verified
The work function of the metal is approximately \(2.49 \, eV\), which corresponds to option (B) \(2.48 \, eV\).

Step by step solution

01

Write down the threshold wavelength and the given constants

We are given the threshold wavelength λ, Planck's constant h, the speed of light c, and the conversion factor between electron volts and joules (1 eV = 1.6 x 10^-19 J). Let's note them. Threshold wavelength, λ = 5000 Ǻ Planck's constant, h = 6.62 x 10^-34 Js Speed of light, c = 3 x 10^8 m/s
02

Convert the threshold wavelength to meters

The threshold wavelength λ is given in angstroms (Ǻ). We need to convert it to meters (m) to match the SI units. 1 Ǻ = 10^-10 m So, λ = 5000 Ǻ x 10^-10 m/Ǻ = 5 x 10^-7 m
03

Use the photoelectric effect equation to find the energy of the photons

According to the photoelectric effect, the energy E of the photons in terms of the wavelength λ can be calculated by the following equation: E = h * (c / λ) Substitute the given values into the equation: E = (6.62 x 10^-34 Js) * (3 x 10^8 m/s) / (5 x 10^-7 m) E = 3.98 x 10^-19 J
04

Convert the energy to eV (electron volts)

Finally, we need to convert the energy from Joules (J) to electron volts (eV). Remember, 1eV = 1.6 x 10^-19 J. So, E (eV) = E (J) / (1.6 x 10^-19 J/eV) E (eV) = (3.98 x 10^-19 J) / (1.6 x 10^-19 J/eV) E (eV) ≈ 2.49 eV It is clear that the work function of this metal is approximately 2.49 eV, which corresponds to option (B) 2.48 eV.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

An electron enters perpendicularly into uniform magnetic field having magnitude \(0.5 \times 10^{-5} \mathrm{~T}\). If it moves on a circular path of radius \(2 \mathrm{~mm}\), its de - Broglie wavelength is $\ldots \ldots . . . \AA$ (A) 3410 (B) 4140 (C) 2070 (D) 2785

Calculate the energy of a photon of radian wavelength \(6000 \AA\) in \(\mathrm{eV}\) (A) \(20.6 \mathrm{eV}\) (B) \(2.06 \mathrm{eV}\) (C) \(1.03 \mathrm{eV}\) (D) \(4.12 \mathrm{eV}\)

A proton and an \(\propto\) -particle are passed through same potential difference. If their initial velocity is zero, the ratio of their de Broglie's wavelength after getting accelerated is \(\ldots \ldots\) (A) \(1: 1\) (B) \(1: 2\) (C) \(2: 1\) (D) \(2 \sqrt{2}: 1\)

\(11 \times 10^{11}\) Photons are incident on a surface in \(10 \mathrm{~s}\). These photons correspond to a wavelength of \(10 \AA\). If the surface area of the given surface is \(0.01 \mathrm{~m}^{2}\), the intensity of given radiations is \(\ldots \ldots\) $\left\\{\mathrm{h}=6.625 \times 10^{-34} \mathrm{~J} . \mathrm{s}, \mathrm{c}=3 \times 10^{8}(\mathrm{~m} / \mathrm{s})\right\\}$ (A) \(21.86 \times 10^{-3}\left(\mathrm{~W} / \mathrm{m}^{2}\right)\) (B) \(2.186 \times 10^{-3}\left(\mathrm{~W} / \mathrm{m}^{2}\right)\) (C) \(218.6 \times 10^{-3}\left(\mathrm{~W} / \mathrm{m}^{2}\right)\) (D) \(2186 \times 10^{-3}\left(\mathrm{~W} / \mathrm{m}^{2}\right)\)

Work function of metal is \(4.2 \mathrm{eV}\) If ultraviolet radiation (photon) having energy \(6.2 \mathrm{eV}\), stopping potential will be........ (A) \(2 \mathrm{eV}\) (B) \(2 \mathrm{~V}\) (C) 0 (d) \(10.4 \mathrm{~V}\)
See all solutions

Recommended explanations on English Textbooks

English Grammar Summary

Read Explanation

Lexis and Semantics

Read Explanation

Graphology

Read Explanation

Language and Social Groups

Read Explanation

5 Paragraph Essay

Read Explanation

Phonology

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free