{"product_id":"planck-s-constant-kit","title":"Planck S Constant Kit","description":"\u003cp\u003ePlank's Constant kit can be used:\u003cbr\u003e• As a direct method that gives a reasonable order of magnitude value for Planck’s constant, h\u003cbr\u003e• For the demonstration of photoelectric effect and the principle of applying a backing p.d. to reduce anode current to zero\u003cbr\u003eThe Planck’s Constant Kit contains a photoelectronic unit, with six colour filters and a BNC to 4mm plug lead. The main unit contains a photoemissive Caesium Antimony cathode, with a spectral response of 185-650nm. When light of frequency, f, strikes the cathode, electrons of energy E=hf-W0 are released and would normally reach the anode, producing a current which can be registered on a very sensitive instrument such as a Picoammeter or an Electrometer.\u003cbr\u003eThe p.d. from an internal PP3 (6F22)-type cell can be adjusted to a value V where the anode current is just reduced to zero. V is proportional to the frequency of light used. This apparatus enables values of V to be found for various frequencies of light selected by placing each of the colour filters in turn over the cell. A plot of V vs. f gives a reasonable straight line where the gradient is h\/e.\u003cbr\u003eItems in the kit are available separately, and also a set of three narrow band filters for mercury violet, green and yellow lines from the spectrum of a mercury discharge lamp. These give a similar graph of the same gradient.\u003cbr\u003eContents include one of each of the following (which are available separately):\u003cbr\u003e• Planck’s Constant Unit with screened lead\u003cbr\u003e• Colour Filters set of six for F4H28615\u003cbr\u003e• Set of 3 Narrow band filters\u003cbr\u003ePlus the following metering:\u003cbr\u003e• Easy-Read Meter\u003cbr\u003e• 20V d.c. Attachment\u003cbr\u003e• Spacesaver Picoammeter\u003c\/p\u003e","brand":"Optika","offers":[{"title":"Default Title","offer_id":51272730345755,"sku":"HC1010338","price":1624.99,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0915\/4363\/4203\/files\/H76701-1_1f4f0cb1-1814-4066-8138-a13fdbefc4b3_20_1.jpg?v=1769447562","url":"https:\/\/abcschoolsupplies.ie\/products\/planck-s-constant-kit","provider":"ABC School Supplies ","version":"1.0","type":"link"}