Competishun Header
Competishun
Contact Us
Back

Report Issue

JEE MAIN 2021
25-07-21 S2
Question
When radiation of wavelength $\lambda$ is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8 V . If the same surface is illuminated by radiation of double the previous wavelength, then the stopping potential becomes 1.6 V . The threshold wavelength of the metal is :
Select the correct option:
A
$2 \lambda$
B
$4 \lambda$
C
$8 \lambda$
D
$6 \lambda$
✓ Correct! Well done.
✗ Incorrect. Try again or view the solution.
Solution
Solution Image
Question Tags
JEE Main
Physics
Medium
Start Preparing for JEE with Competishun
YouTube
Books
App
Tests
Filters 0
JEE Main
JEE Advance
Easy
Medium
Hard
Showing 18 questions
QJEE ADVANCE 20062006
Match the following:
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
According to Bohr's theory, $\mathrm{E}_{\mathrm{n}}=$ Total energy $\mathrm{K}_{\mathrm{n}}=$ Kinetic energy $\mathrm{V}_{\mathrm{n}}=$ Potential energy $\mathrm{r}_{\mathrm{n}}=$ Radius of $\mathrm{n}^{\text {th }}$ orbit...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Match the following:
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Match the extraction processes listed in Column I with metals listed in Column II:
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
The edge length of unit cell of a metal having molecular weight $75 \mathrm{~g} / \mathrm{mol}$ is $5 \AA$ which...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
We have taken a saturated solution of $\mathrm{AgBr} . \mathrm{K}_{\text {sp }}$ of AgBr is $12 \times 10^{-14}$. If $10^{-7}$...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 2006 2006
For the reaction, $2 \mathrm{CO}+\mathrm{O}_2 \longrightarrow 2 \mathrm{CO}_2 ; \Delta \mathrm{H}=-560 \mathrm{~kJ}$. Two moles of CO and one mole of...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
75.2 g of $\mathrm{C}_6 \mathrm{H}_5 \mathrm{OH}$ (phenol) is dissolved in a solvent of $\mathrm{K}_{\mathrm{f}}=14$. If the depression in freezing point...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Ammonia is always is added in this reaction. Which of the following must be incorrect?
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
When ammonia is added to the solution, pH is raised to 11 . Which half-cell reaction is affected by pH...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Find $\ln K$ of this reaction.
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
A nuclear explosion has taken place leading to increase in concentration of $C^{14}$ in nearby areas. $C^{14}$ concentration is $C_1$...
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
What should be the age of fossil for meaningful determination of its age?
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Which of the following option is correct?
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
The hybridization of A and B are
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
Predict the magnetic nature of A and B .
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
The IUPAC name of $A$ and $B$ are
JEE AdvanceChemistryEasy
View Solution→
QJEE ADVANCE 20062006
What are the constituent amines formed when the mixture of (i) and (ii) undergoes Hofmann bromamide degradation?
JEE AdvanceChemistryEasy
View Solution→