KVPY Class-XI (...

The number of positive integers n in the set {2, 3,...., 200} such that 1/n has a terminating decimal expansion is

If a, b and c are real numbers, such that a + b + c = 0 and a² + b² + c² = 1, then (3a + 5b - 8c)² + (-8a + 3b + 5c)² + (5a - 8b + 3c)² is equal to

Let S be a set of all ordered pairs (x, y) of positive integers, with HCF(x, y) = 16 and LCM(x, y) = 48,000. The number of elements in S is

Consider a set A of natural numbers n whose units digit is non-zero, such that if this units digit is erased, then the resulting number divides n. If K is the number of elements in the set A, then

There are exactly twelve Sundays in the period from January 1 to March 31 in a certain year. Then, the day corresponding to February 15 in that year is

Consider a three-digit number with the following properties.

I. If its digits in units place and tens place are interchanged, then the number increases by 36.
II. If its digits in units place and hundreds place are interchanged, then the number decreases by 198.

Suppose that the digits in tens place and hundreds place are interchanged. Then, the number

The particles used in the Rutherford's scattering experiment to deduce the structure of atoms

The number of completely filled shells for the element ₁₆S³² is

The refractive index of water in a biology laboratory tank varies as 1.33 + 0.002/λ², where λ is the wavelength of light. Small pieces of organic matter of different colours are seen at the bottom of the tank using a travelling microscope. Then, the image of the organic matter appears

The acidity of compounds I-IV in water

I. Ethanol
II. Acetic acid
III. Phenol
IV. Acetonitrile

follows the order:

The reddish-brown precipitate formed in the Fehling's test for aldehydes (RCHO) is due to the formation of

White phosphorus catches fire in air to produce dense white fumes. This is due to the formation of

The maximum number of electrons that can be filled in the shell with the principal quantum number n = 4 is

The oxidation states of P atom in POCl₃, H₂PO₃, and H₄P₂O₆ respectively are

A solution (5 mL) of an acid X is completely neutralised by y mL of 1 M NaOH. The same volume (y mL) of 1 M NaOH is required to neutralise 10 mL of 0.6 M of H₂SO₄ completely. The normality (N) of the acid X is

According to Watson-Crick model, hydrogen bonding in a double-stranded DNA occurs between

Which of the following statements about mitosis is CORRECT?

Gaseous exchange of oxygen and carbon dioxide between alveolar air and capillaries takes place by

Of the periods listed below, which is the earliest when ostracoderms, the jawless and finless fishes, appeared?

Scurvy is caused by the deficiency of

Optical activity of DNA is due to its

The monarch butterfly avoids predators such as birds by

Filariasis is caused by

Which of the following conversions does NOT happen under anaerobic conditions?

The number of electrons required to reduce one molecule of oxygen to water during mitochondrial oxidation is

Which of the following molecules is derived from pantothenic acid?

Match the disease given in Column I with the principal causal organism in Column II and choose the correct combination:

Which of the following options lists the primary energy sources for all forms of life on Earth?

In an in vitro translation experiment, poly (UC) RNA template produced poly (Ser-Leu), while poly (AG) RNA template produced poly (Arg-Glu) polypeptide. Which of the following options represents correct interpretations of the codon assignments for Ser, Leu, Arg, and Glu?

A single bacterium is actively growing in a medium that supports its growth to a number of 100 million. Assuming the division time of the bacterium as 3 hours and the life span of non-dividing bacteria as 5 hours, which ONE of the following represents the maximum number of bacteria that would be present at the end of 15 hours?

A couple has two sons and two daughters. Only one son is colour blind and the rest of the siblings are normal. Assuming colour blindness is sex-linked, which ONE of the following would be the phenotype of the parents?