Questions
Differentiate: Pinus and Peepal.
Differentiate: Moss and Club moss.
Differentiate Jelly fish and Cuttle fish.
Differentiate: Fish and Star Fish.
Differentiate: Plant kingdom and Animal kingdom
Prove that: Unit of electric resistance ohm($\Omega$) = kgm2s-3A-2.
Manisha wanted to test the eating habits of her dog. She decided to study how the amount of food and the time of giving food affects the speed at which the dog ate. What is wrong with the design of Manisha's experiment and how can she correct it?
Subodh wanted to find out how the colour of an object affects its ability to hold heat. For that, he took four conical flasks and coated the first flask with black coloured enamel, the second flask with white enamel, the third with green enamel and the fourth with red enamel. Then, he filled all the flasks with water, closed the mouth of each flask tightly with cork and then kept them in the sun. After some time he measured the temperature of water in each flask with the help of a thermometer and noted the readings. Identify the independent variable and dependent variable in Subodh's experiment. Which variables should be controlled by Subodh?
Chandani wanted to investigate the effects of substances mixed with the soil on plant growth. She decided to mix lime, urea fertilizer, common salt, and compost manure in the soil. Then she brought a bucket of soil from a nearby field and sieved it. She put that soil equally into 12 uniform-sized pots. Then she mixed two spoons of salt in every three pots, two spoons of urea fertilizer in each of the next three pots, two spoons of table salt in each of the next three pots and finally, two spoons of compost fertilizer in each of the remaining three pots. She then planted similar seeds of the same plant in every pot and placed them all in a sunny place in the house. She watered all the pots every day. After the plants grew, she measured the height of each plant daily and kept a record.
i) Identify the independent variable, the dependent variable and controlled variable in Chandani's experiment.
ii) Why did Chandani use 3 pots for each experiment?