Landslides, Flash Floods: You Better Avoid These Places In July | Tripoto #Shorts

It is possible to take a high quality photograph of a very fast moving object by illuminating the object for quite a small fraction of a second. You may have come across photographs of a bullet penetrating a banana or an apple in many text books or magazines. This is called 'stop action' photography because the fast moving object travels a very short distance during the time of illumination. Harold Edgerton, the inventor of stroboscope, was a pioneer of this kind of photography. A normal photographic plate works properly if it receives an energy of 4J during the exposure. To release this energy in a very small fraction of time, huge amount of power is required. Such huge power can not be generated directly from a battery because of its high internal resistance. To produce such power a capacitor is used. The time in which a capacitor discharges can be very short. Although, theoretically it would take a long time for a capacitor to discharge completely, it discharges almost completely in about 10 time constant. Consider the following situation A capacitor of 200muF storing 4J energy is made to discharge through a flash light in 2ms. This setup is used to take the picture of a bullet moving at a speed of 100m//s Assume that the flash light acts as a resistor and there is no other resistance in the circuit. What is the order of energy delivered to the flash light in 0.2 ms(approx).