Physics · Ch 8 — Atomic and Nuclear Physics
ICT Corner
ICT Corner
The chapter ends with an "ICT Corner" activity box directing students to a free online virtual-lab simulation of Millikan's oil drop experiment, hosted at the Amrita Vishwa Vidyapeetham virtual labs portal (vlab.amrita.edu), so that students without access to the real, delicate physical apparatus can still carry out the timing measurements and force-balance calculation themselves. The activity's stated learning goals are to let a student experimentally demonstrate the concept of Millikan's oil drop experiment, find the terminal velocity of a simulated drop under two different conditions, and use those measurements to calculate the electric charge carrie …
Worked out. This activity walks a student through reproducing Millikan's oil drop experiment as an online simulation rather than a physical apparatus: after opening vlab.amrita.edu and navigating to Physical Sciences, then Modern Physics Virtual Lab, then Millikan's oil drop experiment, the student starts the simulation, chooses an oil, and times how long a drop takes to fall a measured distance l1 with the field off to compute its free-fall terminal velocity v1 = l1/t1. Next, the student switches the voltage on to suspend the same drop and notes the balancing voltage V, then switches on the X-ray source (used to occasionally recharge the drop) and again times its motion over a distance l2 to get a second terminal velocity v2 = l2/t2. Finally the charge on the drop is computed from q = 6 pi eta r (v1 + v2) / V, using the drop's radius r (measurable via the built-in telescope) and the viscosity of air eta = 1.81e-5 kg per metre per second, giving s …