Which of the following statements is incorrect?
A We should allow sunlight to our house because it helps to kill germs and decrease humidity.
B We should put wire mesh on the windows to stop the entry of dust and light.
C We should welcome our guests in the living room of our house.
D We should use bricks, cement, etc. to make our permanent houses as they make a house strong.
Dharini took two healthy green plants of equal size, put them in two boxes, L and M, made of different materials and placed them under the Sun, as shown in the figures. She watered both the plants daily, but the plant in set-up M died, while the plant in set-up L grew well. Which of the following best describes this?
APlant in the set-up M could not get air.
BBox in the set-up M is made up of clear glass.
CPlant in the set-up M could not get sunlight.
DBox in the set-up L is made up of wood.
the answer is C
The picture shows a xylophone. A, B, C and D are the rods in it. Which of the following rods has high pitch of the sound and which has low frequency of vibrations?
|High pitch||Low frequency|
|B||B and C||B and C|
|C||A and D||A and D|
Which of the following represents the correct increasing order of the densities of given substances?
A Cotton < Exhaust from chimneys > Honey < Iron < Air
B Air < Exhaust from chimneys < Cotton < Honey < Iron
C Cotton < Air < Exhaust from chimneys < Iron < Honey
D Air < Cotton < Exhaust from chimneys < Iron < Honey