purchase of physics lab equipments purchase of physics lab equipments as per boq , physics lab equipments , melde’s string experiment –setup to find the frequency of an electrically vibrating metal tip.melde’s apparatus electrical vibrator of frequency 50 hz with ac power supply, 3 meterlength of strong white cord, bench clamp and pulley for attachment to the edge of a bench, plastic scale pan with hook to carry weights for tensioning the cord. , photo-electric effect, - complete setupto determine the planck’s constant planck constant by photoelectric effect : photosensitive device : cs vacuum photo tube , light source : halogen tungsten lamp12v/35w , color filters : 635nm(red), 570nm(orange), 540nm(yellow), 500nm (green), 460nm (blue), accelerating voltage : -15v to ov & o to 15v, < ± 2% , output : ±15v continuously variable through multi-turn pot , display : 3½ digit 7-segment led , accuracy : ±0.2% , current detecting unit : digital nano ammeter , range : 10001.1a, 1001.1a, 10[ta a 1 ?a , resolution : 1na , display : 3½ digit 7-segment led , accuracy : ±0.2% , power requirement : 220v ± 10%, 50hz , current multiplier : ×1, × 0.1, ×0.01 & ×0.001, scale : length 400 mm , dark- current : < 0.003?a , measuring error : < ± 15% compared with the recognized value (h=6.62619 ×10-34j.s) . .