Science Olympiad Mock Test - 1 - Class 6 MCQ

After interchanging × and ÷,
We get
6 + (9 - 3) × (8 + 1) ÷ (7 - 4) = 6 + 6 x 9 ÷ 3 = 24

This is an alternating subtraction series in which 2 is subtracted twice, then 3 is subtracted once, then 2 is subtracted twice, and so on.

Grandfather's son means either son or uncle.
Mother of uncle or son is grandmother.

The atoms of carbon can be bonded together in different ways, termed 'allotropes of carbon'. The best known are graphite, diamond, and amorphous carbon. The physical properties of carbon vary widely with the allotropic form.  

When a beam of light strikes an unpolished wooden surface, there will be a diffused reflection as an unpolished wooden surface is irregular, and not smooth.  

Earthworms can breathe inside the soil. They come outside only when water takes the place of air in the soil.  

The handle of a screw-driver is made of rubber or plastic, as rubber and plastic are bad conductors of electricity.  

Light is a form of energy produced by a luminous object. An object is considered luminous if it emits its own light.  

An aqueous solution turns blue litmus solution red, it means the given solution is acidic in nature. Since sodium hydroxide is basic in nature, the excess addition of sodium hydroxide would change the nature of the solution to basic. Therefore, the basic solution turns red litmus solution to blue again.  

Sodium chloride (NaCl) is the classic case of ionic bonding. The sodium chloride molecule is formed by the ionisation of sodium and chlorine atoms, and the attraction of the resulting ions.  

Carbon dioxide passed into limewater gives a milky solution. This is due to the insoluble suspension of calcium carbonate formed. Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l)  

Citric acid is responsible for the sour taste of orange juice.  

In olden days, shadows caused by objects placed in the sun were used to measure time. Such a device is called a sundial or Samrat Yantra. 

Curdling of milk is an irreversible change because the product so obtained cannot be changed into its original form. Curd cannot become milk again.  

Threshing is the process of removing the grain of wheat or barley from the stalk and husk. It is done in different ways, depending on how much grain there is. Essential to threshing is a threshing floor, a flat area of hard rock, on which freshly harvested wheat could be piled.  

Vitamin K is required for clotting of blood. 

Vitamin C is essential for healing bleeding gums and wounds. Citrus fruits like oranges, grapes, lemons, tomatoes should be eaten in this situation.  

In a leap year, there are 29 days in February. So, if he has one exam after 5 days, which are 27th, 28th, 29th, 1st and 2nd, so he will have his next exam on 3rd of March.  

If Wednesday is on 10th, then Sunday is on 14th. So, it means that the anniversary is on 14th.  

Each time, we are multiplying by 2 and then adding 2. 43 x 2 = 86 + 2 = 88 88 x 2 = 176 = 176 + 2 = 178 (actual) 178 x 2 = 356 + 2 = 358 So, 179 is the odd one out..  

If a magnet is left to itself over a long period of time, it gets demagnetised, i.e. it loses its magnetic property.  

Glass sheet is a transparent object, not an opaque object.
An opaque object is an object through which light cannot pass. The light is either reflected, scattered, or absorbed.

Deficiency of proteins in the diet for a long time results in swelling of the face, swollen neck, undergrowth of the body, etc. This is because proteins are the building blocks of the body and should be taken in sufficient amounts.  

Air is also an important part of soil. Within the soil, pockets of air are trapped. The organisms living in the soil use oxygen from the air trapped in the pockets of the soil.  

Magnesium hydroxide reduces stomach acid and increases water in the intestines which may induce defecation. Magnesium hydroxide is used as a laxative to relieve occasional constipation (irregularity) and as an antacid to relieve indigestion, sour stomach, and heartburn.  

Kwashiorkor is a severe form of malnutrition, caused by a deficiency in dietary protein. Symptoms of Kwashiorkor are: Dark and scaly skin, anaemia, and mental retardation.  

Potatoes, garlic and ginger are underground stems modified to store food.

In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll. Chloroplasts are surrounded by a double membrane and contain a third inner membrane, called the thylakoid membrane, that forms long folds within the organelle.  

Stomata take carbon dioxide from atmosphere and are responsible for the process of photosynthesis.  

Crystallisation is the process by which we can obtain pure solids of copper sulphate.