The atomic number of carbon is 6, the atomic weight is 12. How many protons are there in the nucleus of carbon?
(A) 6
(B) 12
(C) 18
(D) 0
Carbon-12: with 6 protons and 6 neutrons and an atomic mass of 12.
The mobility of conduction band electrons is greater than that of holes because
(A) they are light
(B) they collide less often
(C) they have negative charge
(D) they require less energy to move
In a semiconductor the mobility of electrons (referring to 'conduction electrons' or 'free-electrons') is greater than that of a holes (indirectly referring to 'valence electrons') because of different band structure and scattering mechanisms of these two carrier types
The producers formed by the combustion of magnesium are -
(A) is acidic
(B) is indifferent
(C) alkaline
(D) all
Therefore, the correct option is (C) Magnesium ribbon on burning in air produces: 'Magnesium oxide, heat and light'.
Which of these metals is found in liquid state?
(A) Iron
(B) Mercury
(C) Silver
(D) Others
Mercury is the only metal that is liquid at normal temperatures.
The element absorbed in both cation and anion forms is:
(A) Sulfur
(B) Nitrogen
(C) Calcium
(D) Phosphorus
Nitrogen is absorbed in both cationic (NH4+) and anionic (NO3-) form. Sulphur, phosphorus and boron are absorbed only in anionic forms.
Which of the following plants is not a collection organ of a stem?
(A) Sugarcane
(B) Ginger
(C) Potato
(D) Sweet potato
In which branch do you study flowering plants?
(A) Cryptogames
(B) Phanerogames
(C) Bryophytes
(D) Pteridophytes
Plant & flower science: Botany is the branch of biology that deals with plants. It involves the study of the structure and properties of plant life, including flowers and trees. Also included are plant classification and the study of the interactions of plants with their physical environment.
The monkey is placed in which of the following union?
(A) Mamlas
(B) Reptilia
(C) Insecta
(D) pieces
A primate is any mammal of the group that includes lemurs, lorises, tarsiers, monkeys, apes, and humans. The order Primates, with its 300 or more species, is the third most diverse order of mammals, after rodents and bats.
What is the endosperm of the embryo helpful in?
(A) Respiration
(B) Protection
(C) Digestion
(D) Emissions
An endosperm provides food and nourishment to the developing plant embryo in angiosperms.
Which of the following is a disease caused by bacteria?
(A) Titanus
(B) Malaria
(C) Poliomyelitis
(D) Filaria
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