DWQA User Profile AdminQuestions(0)Answers(5)Posts(8)CommentsSorry for the delay in posting the answer to quiz questions.Quiz questions:1.In case the digital weighing scale is out of calibration by say -10% of the reading i.e any weight it displays less by 10% of its actual weight. For example 100gm is displayed as 90 gram, 500 gram is displayed as 450 gram, 1000 gram is displayed as 900 gram and so on. In what way it is going to affect the result? Will it result in a density value be:-a)Less by 10%b)More by 10%c)No effectd)UnpredictableAnswer:The digital scale is stated to be out of calibration by -10% of the reading. This means there is no zero error and it indicates 0.9 of the actual weight. In other words the calibration is perfectly linear. Since the volume is being computed from the weight of displaced water, the resultant volume is also affected by a factor of 0.9, in the identical way as the weight of the object. Again the density is computed by dividing the indicated weight of the object and computed volume, both of which are affected by a factor of 0.9, resultant density value will remain unaffected.So the answer is “c”It may me noted as long the calibration of the weighing scale is linear, the result of experiment remain unaffected. Any zero error of the scale gets cancelled out as we tare the scale i.e zero the scale at the beginning.2.In case we carry out same experiment laboratory in a place where gravity is less than that on earth surface. Say for example we conduct it on the surface of moon where gravity is 1/6th earths gravity on its surface. In what way it is going to affect the result? Will it result in a density value be:-a)It will result in lower density valueb)It will result in higher density valuec)It will result in correct density valued)Cannot be predictedAnswer:Weight of any object is the force experienced by it due to gravity, which is product of mass and acceleration due to gravity experienced by it. As both the measurements get reduced by a factor 1/6 compared to those on the earth surface, the resultant density value will remain unaffected.So the answer is “c”3.Let us in the experiment by replacing the tap water with sea water. In what way it is going to affect the result? Will it result in a density value be:-a)It will result in lower density valueb)It will result in higher density valuec)It will result in correct density valued)Cannot be predictedAnswer:While carrying out the experiment with tap water we assumed the density to be 1 gram per cc for all practical purposes. But sea water is denser by 2 to 3 percent. So the weight of the displaced volume of water will be higher by 2 to 3 percent. Therefore, unless we consider the correct density the water the resultant computed volume will be lesser by 2 to 3 percent.So the answer is “a”The experiment we conducted will result in quite an accurate value of the density of the object for the purpose of identification of the material. However this is based on certain assumption and precautions:1.The object is heavier that water.2.The object is not soluble in water. If it is soluble in water, replace water with liquid like kerosene but with known density and density correction to be done.3.The object is fully solid. In case the object has a hollow space inside by design, the density obtained will be lower. If the volume of hollow space is known, it can be deducted from the computed volume to obtain the correct value of the material.4.While immersing the object no air is trapped inside or stuck to surface of the object. This will give increased volume measurement.5.The object is made up of one material. If it is made up of multiple material average density will be obtained. For plated objects the error will be minuscule as the plating thickness is in normally in few microns.6.The object does not touch the surface of the container.7.The object is fully immersed and not touching the water surface, else surface tension force may come into play.8.The thread used to hang the object has negligible dimension, as its volume and weight will add to the measured volume and weight.9.The object has not been taken out during the experiment. It taken out in between, the water attached to the surface of the body may drip outside and alter the results.10.The density of water varies with temperature and dissolved contents. It has been assumed to 1 gm per cc. For more accurate result distilled water should be used and density should be corrected for temperature.11.Although the accuracy of the weighing scale has no effect on the result provided the calibration is linear. More the linearity should more accurate will be result.12.More the resolution of the scale more accurate will be the result.13. The table on which experiment is conducted should the stable and should not have movements.14.Air movements around should be minimum. Air movement due to fan can cause observable weight error.15.If the object is magnetic or magnetized, nearby magnetic structure will cause weight measurement erroneous.The list could be bigger. The idea is to be aware of the fact that so many parameters which affect the accuracy of the experimental result in any experiment. More we are aware of these parameters/ condition and better we control the better will be the accuracy of the experimental results.Please feel free to point out any correction needed if any and also to improve answers.On It glitters. Is it Gold?Jai HoOn My Near Ghost ExperienceThanks once againOn Living For A PurposeThank you so much for the words of appreciation.On GodsendThank you so much for words of appreciation. It motivates me to write more.On My Near Ghost ExperienceThanksOn It glitters. Is it Gold?Thanks. I will post the answers wit explanation after some timeOn It glitters. Is it Gold?Thanks. I will post the answers wit explanation after some timeOn It glitters. Is it Gold?Hi Chetna,I am so glad that you could relate to my near ghost experience story. I was a city bred person, totally unaware of such kind of loneliness and wilderness. Initially it was difficult, but eventually I fell in love with that place. I miss that place always more so in my dreams. My life there was my golden days and full of experiences of exotic kinds. I always wish to share as many of them as possible. If it resonates with even one person like it did with you, it will be my reward.You have a very good writing skill, very expressive. Keep writing whatever you feel like and share with people. Definitely you will enjoy. All the best.BishwajitOn My Near Ghost Experienceyou will see more posts slowlyOn My Near Ghost Experiencethanks for the nice wordsOn My Near Ghost ExperiencesureOn My Near Ghost ExperiencethanksOn My Near Ghost ExperiencethanksOn My Near Ghost ExperienceI was posted in Rajasthan for my workOn My Near Ghost Experiencecertainly you will get more postsOn My Near Ghost Experiencenice to knowOn My Near Ghost Experiencethank you for you appreciationOn My Near Ghost ExperienceDid you get disappointed?AdminOn Be and speak positiveThanks for the observationOn Living For A PurposeThank you for reading the storyOn Living For A PurposeThanks for commentOn Living For A PurposeI agreeOn Living For A PurposeVery touchingOn Living For A PurposeApprovedOn ASK ME ANYTHINGThanks for your query!I will get back on this soon.On ASK ME ANYTHINGCrop
