Class 12th

A thick current carrying cable of radius ' R' carries current ' I ' uniformly distributed across its cross-section. The variation of magnetic-field B(r) due to the cable with the distance 'r' from the axis of the cable is represented by:

A nucleus with mass number 240 breaks into two fragments each of mass number 120, the binding energy per nucleon of unfragmented nuclei is 7.6MeV while that of fragments is 8.5MeV. The total gain in the Binding Energy in the process is:

The correct IUPAC name of the following compound is:

The order of energy absorbed which is responsible for the color of complexes.
(A) [Ni(H₂O)₂(en)₂]²⁺
(B) [Ni(H₂O)₄(en)]²⁺
(C) [Ni(en)₃]²⁺

A nucleus of mass number 189 splits into two nuclei having mass number 125 and 64 . The ratio of radius of two daughter nuclei respectively is :

In the neutral or faintly alkaline medium, KMnO₄ oxidises iodide into iodate. The change in oxidation state of manganese in this reaction is from:

The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

Find the emf of the cell in which the following reaction takes place at 298 K
Ni(s) + 2Ag⁺(0.001M) → Ni²⁺(0.001M) + 2Ag(s)
(Given that E°cell = 1.05 V, 2.303RT/F = 0.059 at 298 K)

Given below are two statements:

Statement I: In Lucas test, primary, secondary and tertiary alcohols are distinguished on the basis of their respectively with conc. HCl + ZnCl₂, known as Lucas Reagent.
Statement II: Primary alcohols are most reactive and immediately produce turbidity at room temperature on reaction with Lucas Reagent

In the light of the above statements, choose the most appropriate answer from the options given below:

Match List -I with List -II

List -I (Ores)
(a) Haematite
(b) Magnetite
(c) Calamine
(d) Kaolinite

List-II (Composition)
(i) Fe₃O₄
(ii) ZnCO₃
(iii) Fe₂O₃
(iv) [Al₂(OH)₄Si₂O₅]

Choose the correct answer from the options given below: