Which one of the following facts provides the best evidence that matter may exist as tiny particles which can move at random?
A A drop of oil forms a very thin layer on the surface of water.
B Most metals conduct electricity.
C People in an enclosed space soon notice when medicated oil is being used
D A quantity of air can be compressed into a much smaller volume.
The table below shows the amount of water used by 4 different families in April, May, June and July. All 4 families watched a water conservation (save water) programme in May. Which family is likely to have understood the reason behind conservation of water?
(A) Family 1
(B) Family 2
(C) Family 3
kindly give explanation of this question
Shruti in an experiment, put a healthy, green plant in different conditions during a day, at different times P, Q and R. The rate of oxygen absorbed or released by this plant is shown in the given graph.
Which of the following assumptions can be made about this experiment?
AAt time P, that plant was put in a dark cupboard.
BAt time Q, plant is not respiring because, no oxygen is being taken up.
CAt time Q, the plant was moved to a dark room.
DAt time R, the plant was put in a well lighted place.
The answer given by Olympiad trainer is B but We all know that plants respire all the time. May I know the right answer
Which of these statements is INCORRECT?
ACranes used to lift loads use pulleys.
BA wedge is made up of two inclined planes.
CFork is an example of lever.
DScrew is used to lower and raise things.
HOW ARE SCREWS USED FOR RAISING AND LOWERING
Study the given diagram carefully and select the correct option regarding it.
ALeaves Q and R cannot make food.
BLeaves P and Q cannot make food.
CTo leaves Q and R, sunlight is not available.
DTo leaf P, water is not available.
The given diagram shows a hill with four labelled positions W, X, Y and Z. When a ball is rolled down the hill, then from which position will it finish rolling with the greatest speed?
(A) Position W
(B) Position X
(C) Position Y
(D) Position Z