The study of free fall and the pendulum is one of the most fundamental studies in mechanics and early physical constants students must derive and observe .For determination of gravitational constant 'g'  by free fall method. The apparatus comprises of an electromagnet which is housed in a plastic moulded case with 4mm socket connections provided to energize the magnet and another pair of sockets for connection to the timers in use. The electromagnet is energized and a metal sphere provided  is attached. As soon as the power to the electromagnet is switched off the sphere falls and the unit activate the timer. The sphere hits a platform which is connected to a micro switch which then stops the timer and the time of fall can be determined. Complete apparatus  includes  base stand, spheres and digital timer Supplied with stand.