NCERT 12 Chemistry General Principles and Processes Of Isolation of Elements Chapter 6 Exercise 1

Q.6.1. Suggest a condition under which magnesium could reduce alumina. Ans. The two redox reactions are : Q.6.2. Although thermodynamically feasible, in practice, magnesium metal is not used for the reduction of alumina in the metallurgy of aluminium. Why? Ans. Below the temperature (1623 K), corresponding to the point of intersection of Al2 O3 and […]

NCERT 12 Chemistry General Principles and Processes Of Isolation of Elements Chapter 6 Exercise 2

Q.6.1. Which of the ores mentioned in Table 6.1 page 6/2 can be concentrated by magnetic separation method ? Ans. Ores which are magnetic in nature can be separated from the non-magnetic gangue particles by magnetic separation. For example, ores of iron such as haematite (haematite (Fe2O3), magnetite ( FeCO3) and iron pyrites(FeS3) being magnetic […]

NCERT 12 Physics Semiconductor Electronics Materials, Devices And Simple Circuits Chapter 14 Exercise

Q.1. In n- type which of the following statement is true: (a) Electrons are majority carriers and trivalent atoms are the dopants (b) Electrons are minority carriers and pentavalent atoms are the dopants (c) Holes are minority carriers and pentavalent atoms are the dopants (d) Holes are majority carries and trivalent atoms are the dopants […]

NCERT 12 Physics Dual Nature Of Radiation And Matter Chapter 11 Exercise

Q.1. find the (a) maximum frequency and (b) minimum wave-length of X- rays produced by 30 KV electrons. Given, h = 6.6310-34 Js. Q.2. the work function of caesium metal is 2.14 eV. When light of frequency 6⨯1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the (a) maximum kinetic […]

NCERT 12 Maths Solutions of Inverse Trigonometric Functions – Chapter 2 (Ex.2.1)

NCERT 12 Maths Inverse Trigonometric Functions – Chapter 2 (Ex.2.1), NCERT Class 12 maths chapter 2 solutions. Direction (Q. No. 1 to 10) Find the principal values of the following questions. Direction (Q. Nos. 11 to 14) Find the values of the following questions: Direction (Q. Nos. 11 to 14) Find the values of the […]

Biology 12 Organism and Populations Chapter 13 – Exercise

Biology 12 Organism and Populations Chapter 13 – Exercise, Q 1. How is diapause different from hibernation? Ans 1. Hibernation is the phenomenon commonly depicted by ecothermal (cold-blooded) animals which escape cold by hiding them in shelters such as caves, burrows, cervices, hollow thee trunks, mud etc. revealing minimum physiological activity. This phenomenon is also […]

NCERT 12 Physics Magnetism And Matter Chapter 5 Exercise

Q.1. Answer the following questions regarding earth’s magnetism. (a) A vector needs three quantities for its specification. Name the three independent quantities conventionally used to specify the earth’s magnetic field. (b) The angle of dip at a location in southern India is about 180. Would you expect a grater or lesser dip angle in Britain […]