I/GCSE Physics Question Analysis Topic: Physics - Short Questions
Exam Questions:
1) Draw graphs showing variation of photoelectric current with applied voltage for two incident radiations of equal frequency and different intensities. Mark the graph for the radiation of higher intensity.
2) Name the parts of the electromagnetic spectrum which is
(a) suitable for radar systems used in aircraft navigation
(b) used to treat muscular strain
(c) used as a diagnostic tool in medicine
Write in brief, how these waves can be produced
3) What is the electric flux through a cube of side 1 cm which encloses an electric dipole?
Answers:
For I/GCSE Physics, you should know:
1) The following graph shows the variation of photoelectric current together with applied voltage. It shows different intensities with the same frequency.
2) (a) Microwaves are suitable for this purpose. Such waves are produced by special vacuum tubes such as Klystrons, magnetrons as well as Gunn diodes.
(b) Infrared is used for this purpose. Such waves are produced by hot objects and molecules, including our own bodies!
(c) X-rays are used for this purpose. When high-energy electrons are abruptly stopped on a metal of a high atomic number, such rays are produced.
3) Since an electric dipole has an equal and opposite charge, the net charge that is enclosed by the cube is zero, i.e. qenc = 0.
In other words, the electric flux passing through the cube is ϕ = qenc / ϵo = 0.
Work hard for your I/GCSE Physics examination!
End of analysis. Great!