RBSE Secondary Science case studies
RBSE Secondary Science · Put your knowledge to work in context.
The Rajasthan Board of Secondary Education (RBSE) Class 10 Science examination is a school-leaving assessment for students in Rajasthan, India. It evaluates understanding of core scientific concepts across five domains: Chemical Substances, World of Living, Natural Phenomena, Effects of Current and Natural Resources, and Practical Skills. The RBSE Secondary Science case studies are 5 cases and about 4,222 words.
1The Four Unlabelled Bottles and the Acid Spill
During a monsoon stock check, a Class 10 laboratory assistant finds four reagent bottles whose labels have washed off. The stock register says the four must be dilute hydrochloric acid, sodium hydroxide solution, sodium hydrogencarbonate solution and sodium chloride solution.
836 words, about 4 min2Two Claims About Light and Photosynthesis
A Class 10 group is asked to prove that light is necessary for photosynthesis, using the iodine test for starch. Team A takes a fresh Coleus leaf that has green and white patches, keeps the whole plant in bright sunlight for six hours, boils the leaf in water, then in alcohol over a water bath, washes it and adds iodine.
835 words, about 4 min3Two Pairs of Spectacles in a Tailoring Shop
In a tailoring shop in a small town, Ramu, aged 48, complains that he must hold a needle about 50 cm from his eye to thread it; at 25 cm the thread blurs. His apprentice Sita, aged 15, can read only the largest letters on the blackboard from her seat 2 m away, and says she sees the board clearly from about 1.5 m.
832 words, about 4 min4The Blown Fuse on a Cold Evening
A house is connected to a 220 V mains supply through a 20 A fuse. The appliances and their marked power ratings are: geyser 2000 W, room heater 1500 W, electric iron 750 W, refrigerator 200 W, four bulbs of 40 W each, one fan of 80 W, and a television of 100 W.
855 words, about 4 min5The Sugar Dissolving Investigation
Four students investigate how the temperature of water affects the time taken for sugar to dissolve completely. Each takes a clean 250 mL beaker with 100 mL of water and records the time for the last crystal to disappear: Student Water temperature Sugar Stirring Time --- --- --- --- --- P 20 °C 5 g lump none 210 s Q 40 °C 5 g lump none 96 s R 60 °C 10 g lump continuous 41 s S 80 °C 5 g lump none 18 s They plot time against temperature, include all four points, draw a smooth curve and conclude: "The rate of dissolving doubles for every 20 °C rise in temperature." Their teacher marks the graph down, not because the numbers are wrong, but because the experiment cannot support the claim as designed.
864 words, about 4 min