{"id":35215,"date":"2016-12-03T16:04:38","date_gmt":"2016-12-03T10:34:38","guid":{"rendered":"https:\/\/www.cbselabs.com\/?p=35215"},"modified":"2021-09-18T15:26:34","modified_gmt":"2021-09-18T09:56:34","slug":"to-study-effect-of-intensity-of-light-by-varying-distance-of-he-source-on-an-ldr","status":"publish","type":"post","link":"https:\/\/www.cbselabs.com\/to-study-effect-of-intensity-of-light-by-varying-distance-of-he-source-on-an-ldr\/","title":{"rendered":"To study effect of intensity of light (by varying distance of he source) on an LDR"},"content":{"rendered":"
Physics Lab Manual<\/a>NCERT Solutions <\/a>Class 12 Physics Sample Papers<\/a><\/p>\n Aim<\/strong><\/span> Apparatus<\/strong><\/span> Procedure<\/strong><\/span><\/p>\n Observation record<\/strong><\/span> Conclusion<\/strong><\/span> Precautions<\/strong><\/span><\/p>\n Question. 1. Mention names of three basic logic gates.<\/strong> Question. 2. What do you mean by logic gate in electronics?<\/strong> Question.3. What are n-p-n and p-n-p transistors?<\/strong> Question. 4. In a transistor, base is made thin and is doped very lightly. Why?<\/strong> Question. 5. When does a diode work as an open switch?<\/strong> To study effect of intensity of light (by varying distance of he source) on an LDR Physics Lab ManualNCERT Solutions Class 12 Physics Sample Papers Aim To study effect of intensity of light (by varying distance of the source) on an LDR. Apparatus Light source, light dependent resistors (L.D.R.s) of different variety, a multimeter (or …<\/p>\n","protected":false},"author":27,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[2],"tags":[],"yoast_head":"\n
\nTo study effect of intensity of light (by varying distance of the source) on an LDR.<\/p>\n
\nLight source, light dependent resistors (L.D.R.s) of different variety, a multimeter (or meter bridge), a source of intense light (a lamp bulb with battery eliminator) and a convex lens.
\nLight Dependent Resistor<\/strong>
\nThe light dependent resistance are the devices for detecting and measuring electromagnetic waves (light etc.). Its working is based upon the principle of variation of the photoconductivity when radiation is incident upon it and absorbed by it.
\nA light dependent resistor is prepared from cadmium sulphide. Its resistance depends upon the intensity and duration of light incident on it.
\nA good quality LDR shows a resistance variation from 1 M\u03a9 in complete darkness to about 10 \u03a9 in full day light. The intensity of light decreases inversely with increase the square of distance.<\/p>\n\n
\n(i) Moving the source to 4 cm distance from the L.D.R. and
\n(ii) Moving the source to 6,8 and 10 cm from L.D.R. and repeating observation three more times.<\/li>\n<\/ol>\n
\n
\n<\/p>\n
\nWhen the distance between light source and L.D.R. increases the resistance of L.D.R. decreases.
\nNote:<\/strong> Same activity can be done by varying the exposure time in steps for same source of light, same LDR and for same distance.<\/p>\n\n
Viva Voce<\/strong><\/span><\/h3>\n
\n Answer.<\/strong> (i) OR gate, (ii) AND gate, (iii) NOT gate.<\/p>\n
\n Answer.<\/strong> The circuit which is used to perform the switching action is called a logic gate.<\/p>\n
\n Answer.<\/strong> An npn transistor consists of a thin p-type layer sandwitched between two thick n-type layers. A p-n-p transistor consists of a thin n-type layer sandwitched between two thick n-type layers.<\/p>\n
\n Answer.<\/strong> Base is made very thin and is doped lightly so that most of the carriers are attracted straight into the collector and very few combine in the base. Therefore, to reduce the Ib<\/sub>\u00a0and to increase Ic<\/sub>\u00a0.<\/p>\n
\n Answer.<\/strong> In reverse bias, a diode works as an open switch.<\/p>\n","protected":false},"excerpt":{"rendered":"