KVPY Class-XI (...

Let t_n be the number of integral-sided triangles with distinct sides chosen from {1, 2, 3, ……., n}. Then, t₂₀ - t₁₉ equals

A block of mass 'M' is at rest on a plane surface inclined at an angle θ to the horizontal. The magnitude of force exerted by the plane on the block is

We are able to squeeze snow and make balls out of it because of

Which of the following phenomena can be demonstrated by light, but not by sound waves in an air column?

The note "Saa" on the Sarod and the Sitar has the same pitch. The property of sound that is most important in distinguishing between the two instruments is

The element 'X' which forms a stable product of the type XCl₄ is

A mixture of NH₄Cl and NaCl can be separated by

Among the following, the pair in which the first compound is ionic and the second compound is covalent is

Sodium oxide dissolves in water to give sodium hydroxide, which indicates its

Arrange the pH values of the following solutions in the correct increasing order:

(i) 0.1 M HCl, (ii) 0.1 M KOH, (iii) Tomato juice, and (iv) Pure water

The atomic radii of the alkali metals follow the order

Saponification is

A concentrated solution of lead nitrate in water can be stored in

Which of the following is/are the smallest in size?

If birds are moved from 30°C to 10°C, their body temperature

Ascorbic acid is a/an

Bile salts

Dietary fibres are composed of

'On the origin of species, by means of Natural selection' was written by

Unlike humans, dogs cannot perspire to get rid of excess metabolic heat. They lose metabolic heat by

Haemodialysis is a treatment option for patients with malfunctions of

An individual has O blood group. His/her blood sample

In warmer weather, curd from milk forms faster because

Seedlings grown in dark

In humans, Rhesus condition can arise when

The part of the human brain that governs memory and intelligence is

Saturated dietary fats increase the risk of heart disease by

Rotation of crops is carried out to

A solid square plate is spun around different axes with the same angular speed. In which of the following choices of axis of rotation will the kinetic energy of the plate be the largest?

Aluminium reduces manganese dioxide to manganese at high temperatures. The amount of aluminium required to reduce one gram mole of manganese dioxide is

The pH of a 10 ml aqueous solution of HCl is 4. The amount of water to be added to this solution in order to change its pH from 4 to 5 is

Proteins are synthesised on

Which of the following allows light to focus in visual perception?

During cell division, if there is one round of chromosome duplication followed by one round of cell division, the number of chromosomes the daughter cells will have as compared to the mother is

Similar type of vegetation can be observed, in the same

Which of the following ecological food chains does NOT represent an erect pyramid of numbers?