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
Which of the following statements are correct?
(i) Cochineal insect is used to eliminate Opuntia.
(ii) Water logging decreases the amount of salts in the soil that increases soil fertility.
(iii) Fertilisers are not readily soluble in water, so they are absorbed by the plants slowly.
(iv) Rust of wheat is a fungal disease.
(v) The practice of growing two or more dissimilar crops in the same field one after the other is called mixed cropping.
A (i), (ii), (iii) and (v) only
B (i) and (iv) only
C (ii) and (iv) only
D (iii), (iv) and (v) only