Showing posts from May, 2014

Electromagnetic Waves

You might have heard people talk of electromagnetic waves. Radio waves, micro waves, visible light etc all form a part of electromagnetic spectrum. Electromagnetic spectrum is just a band or collection of electromagnetic radiations. Now you might think, what is an electromagnetic radiation? Let's dive in and find out.

James Clerk Maxwell first postulated the existence of electromagnetic waves that was confirmed by Heinrich Hertz. Maxwell's equations said that a changing magnetic flux would produce an electric field and changing electric flux would produce a magnetic field. So if you change the electric or magnetic field at high frequencies, it would produce the other and vice-versa. This would give us an electromagnetic wave

A unique characteristic of these electromagnetic radiations are, they can travel even in vacuum. How is this possible? We know that sound needs a medium to travel then how can EM radiations travel in vacuum? Simply because electromagnetic radiations are …

Photoelectric Effect

Photoelectric effect is one of the most fascinating yet simple phenomenon in physics. Heinrich Hertz carried out the experiment in which he took a tube and placed two electrodes in it. He then connected them to a power source. He coated the cathode with cesium metal as it has a low ionization energy, which means less energy is required to free the electrons. When sunlight was allowed to fall on the cathode, there was current in the circuit. The number of electrons the were freed depended on the intensity of the incident light whereas the energy required to free the electrons from the atom depended on the frequency of the incident radiation.

Photoelectric effect could not be explained by considering light in the form of a particle or a wave or electromagnetic radiation. In order to explain black body radiation Max Plank, a German theoretical physicist, considered light as a form of electromagnetic radiation composed of photons. This assumption helped him to explain black body radiation…

Importance Of Wheel In Robotics

After a long time I have come back to write about robotics. This time I am going to give you a little insight about mathematics and physics involved in robotics. This is going to be really interesting, so without wasting time "Let's dive in!".

Robotics is an interplay of mechanics, electronics and programming. As these are all related to science and mathematics, it is not unusual to find mathematics and physics in robotics. When you buy a motor for a robot one must always pay attention to information printed on it, mainly the rpm (rotations per minute) and the torque of the motor. These two quantities can be used to calculate the speed of the motor, force generated by it, its acceleration etc.  To find the speed of the motor you just need the rpm of the motor and the radius of the wheel that you are using. Let's see how to do it. Circumference of a circle = 2*pi*r where 'r' is the radius of the wheel. Rpm tells us how many times a wheel rotates in a minute. I…