Title:
IEEE Exhibits: Fleming’s Left Hand Rule and Total Internal Reflection
Author(s):
Vijayalakshmi Ramesh, Andhra Mahila Sabha P. Obul Reddy Public School, India
Abstract—Two models, based on Fleming’s Left Hand Rule (Electromagnetism) and Total Internal
Reflection (Optics) have been developed by the students of AMS P. Obul Reddy Public School,
Hyderabad with guidance from IEEE volunteers, for display at the Birla Science Centre,
Hyderabad. The students developed the models under the direction of their Physics teacher, Mr.
Bhaskara Sarma, who instructs grades 9 to 12.
The models, the ideas for which were conceived by Mr. Sarma, are based on topics taught in grade 10,
to facilitate a practical understanding of the subject, considering their wide ranging applications in
medicine, industry and day to day life. Kindling the interest of high school students in applied
physics in a manner that provokes questions, generates inquisitiveness and increases their
intellectual appetite goes a long way in generating interest in the subject.
The model on Fleming’s Left Hand Rule is based on the principle of a motor’s working. It comprises
of a magnet and a pair of parallel rails placed perpendicular to the direction of the magnetic field. A thin
cylindrical rod is placed on the rails. When a current is passed through the rails, the rod rolls in
accordance with Fleming’s Left Hand Rule and in keeping with the principle, reversing the direction of
the current reverses the direction of rod’s movement.
The model on Total Internal Reflection comprises of a semi circular glass slab. An incident ray is made
to fall on the semicircular face of the glass slab at varying angles and it is observed that beyond the
critical angle, the refracted ray is internally reflected through the glass slab, in entirety.
The students first developed a prototype for both models. This phase proved to be the most
challenging. In the experiment on Fleming’s Left Hand Rule, ensuring the smooth movement of the
roller, preventing the roller from falling off and procuring magnets of requisite strength proved to be
difficult. In the experiment on Total Internal Reflection, fabricating the glass slab to the required shape
proved challenging.
The students also developed a Multimedia presentation explaining the scientific principles behind the
working of the exhibits and the application of these principles in various devices and equipment.
The paper will present a detailed description of the two exhibits and their
working.
Interactive models of the two exhibits now take a place of pride at the Birla Science Museum, much to
the delight of the students.
I have also had the opportunity of authoring Teacher manuals for six exhibits currently on display
(including the two mentioned above).These manuals describe in detail the scientific principles, the
working mechanism of the exhibits and the application of the principles in engineering and
industry. These manuals were peer reviewed before publication.