HelpContactFor teachers and institutes
>_StemPy Lab
Mock TestsClasses

>_StemPy Lab

Learn. Solve. Code the solutions. Test yourself.

Live examsFree mock exams, timed and rankedEveryone starts together, and your score and rank come the moment it ends.See the exams →

Learn

  • Physics
  • Chemistry
  • Mathematics
  • Biology
  • Python Programming
  • Statistics & Data Science
  • Classes
  • Groups

Practice

  • Problems
  • Quizzes
  • Mock Tests
  • Prepare for an Exam
  • Question Sets
  • Exams
  • Certificates
  • Python Labs
  • AI Practice Generator
  • Student-Created Tests

Community

  • Discussions
  • Resources
  • Notes
  • Blog

Account

  • Log in
© 2026 senLearn. All rights reserved.HelpAboutContactPrivacy PolicyTerms of UseRefund Policy
  1. Problems
  2. /Quantum Mechanics

Quantum Mechanics

Physics

Wave functions, uncertainty, and quantum systems.

+ Upload a Problem
15 problems
Exam:
Type:
1.
A polished copper sphere of radius 5.0 cm hangs on an insulating thread in a large vacuum chamber…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsJEE MainJEE AdvancedOlympiad+25OlympiadStemPy LabStemPy Lab
Hard
2.
A speck of dust has a mass of 1.0 µg. (a) How fast would it have to move for its de Broglie…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsJEE MainBoard ExamAP+27APA-LevelIBStemPy LabStemPy Lab
Hard
3.
Electrons are speeded up by 150 V and hit a crystal whose rows of atoms are 0.215 nm apart…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsAPA-LevelIB+20APA-LevelIBStemPy LabStemPy Lab
Medium
4.
A photon has a wavelength of 500 nm. (a) Find its momentum…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+1APA-LevelIBStemPy LabStemPy Lab
Easy
5.
Two metals A and B give parallel lines on a graph of stopping potential against frequency…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsJEE MainBoard ExamAP+27APA-LevelIBStemPy LabStemPy Lab
Hard
6.
The work functions of six metals are: caesium 2.1 eV, potassium 2.3 eV, lithium 2.9 eV, zinc 4.3…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+21APA-LevelIBStemPy LabStemPy Lab
Medium
7.
A laser pointer sends out 5.0 mW of red light of wavelength 650 nm…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsAPA-LevelIB+20APA-LevelIBStemPy LabStemPy Lab
Medium
8.
A student measures the stopping potential of a metal N…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+1APA-LevelIBStemPy LabStemPy Lab
Easy
9.
A faint ultraviolet lamp gives an intensity of 2.0 × 10⁻³ W/m² on a metal plate with a work…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsJEE MainAPA-Level+26APA-LevelIBStemPy LabStemPy Lab
Hard
10.
A photocell has a cathode with a threshold wavelength of 480 nm…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+21APA-LevelIBStemPy LabStemPy Lab
Medium
11.
A photocell is lit by a violet lamp. The lamp is dimmed until it sends one quarter of its light…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+1APA-LevelIBStemPy LabStemPy Lab
Easy
12.
A metal surface has a work function of 2.4 eV…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsNEETBoard ExamAP+22APA-LevelIBStemPy LabStemPy Lab
Medium
13.
Two beams have the same frequency, and one is much brighter…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+21APA-LevelIBArnieArnie
Medium
14.
The stopping voltage is 0.45 V for light of 6.0 × 10¹⁴ Hz, and 1.68 V for 9.0 × 10¹⁴ Hz…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsNEETBoard ExamAP+22APA-LevelIBArnieArnie
Medium
15.
A metal has a work function of 2.75 eV. Ultraviolet light of 350 nm falls on it…
High School (11–12) · Dual Nature of Radiation and Matter, Quantum MechanicsBoard ExamAPA-Level+1APA-LevelIBArnieArnie
Easy