Which of the following material is a semiconductor?

If \(75\)% of a first-order reaction gets completed in \(32\) minutes, the time taken for \(50\)% completion of this reaction is:

Choose the correct combination(s) :
(A) Nylon 6: Addition Copolymer
(B) Buna-S: Addition homopolymer
(C) Melamine: Condensation Copolymer
(D) Teflon : Addition homopolymer
Choose the correct answer from the options given below :

In the Cell reaction :
\(Mg ( s )+2 Ag ^{+}( aq ) \rightarrow Mg ^{2+}( aq )+2 Ag ( s )\)
\(E _{\text {cell }}^{\circ}=3.17 V\). By doubling the concentration of \(Mg ^{2+}, E _{\text {cell }}\) is :

Which alloy is used for making bullets and lighter flints?

Arrange the following compounds in order of in increasing boiling points:
(A) Bromomethane
(B) Bromoform
(C) Chloromethane
(D) Dibromomethane
Choose the correct answer from the options given below:

Which of the following compounds will be repelled when placed in an external magnetic field?

Which of the following statement(s) is/are incorrect?
(A) The Kirchhoff's laws are equally applicable in alternating current circuit and direct current circuits.
(B) It is not necessary that the wire stretched on the meter bridge must have a uniform cross-sectional area.
(C) The internal resistance of the cell does not affect the reading of the null point in metre bridge.
(D) Electrical potential has no direction, the electrical potential gradient has a direction.

A container contains 48 litres of buffalo milk. From this container 8 litres of buffalo milk was taken out and replaced with cow milk. This process was repeated further 3 more times. How much buffalo milk is there in the container now ?

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Kinetic studies not only help us to determine the rate of a chemical reaction but also describe the conditions by which the reaction rates can be altered. The factors such as concentration, temperature, pressure and catalyst affect the rate of a reaction. The speed of a reaction or the rate of a reaction can be defined as the change in concentration of a reactant or product in unit time.
Rate \(= \text{k}[\text{A}]^x [\text{B}]^y\)
Here k is the rate constant
\(x + y\) gives the overall order of a reaction, whereas \(x\) and \(y\) represent the order with respect to the reactants A and B, respectively.
If the temperature is raised by \(10^\circ\text{C}\), then the rate of the reaction increases approximately by:

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In the formation of coordination complexes, if the inner \(d\) orbital \((n - 1)d\) is used in hybridisation, the complex, is called an inner orbital or low spin or spin paired complex. And if it uses outer \(d\) orbital \((nd)\) in hybridisation (like \(sp^3d^2\)), it is called outer orbital or high spin or spin free complex. The degeneracy of the \(d\) orbitals has been removed due to ligand electron-metal electron repulsions in the complex. This splitting of the degenerate levels due to the presence of ligands in a definite geometry is termed as crystal field splitting. For coordination complexes, the magnetic moment is determined by the number of unpaired electrons and is calculated by using the 'spin-only' formula, \(\mu = \sqrt{n(n+2)}\) where \(n\) is the number of unpaired electrons and \(\mu\) is the magnetic moment in units of Bohr magneton \((BM)\). The coordination compounds are of great importance. These compounds are widely present in the mineral, plant and animal worlds and are known to play many important functions in the area of analytical chemistry, metallurgy, biological systems, industry and medicine.
Fe(II) octahedral complexes can show different 'spin only' magnetic moments for arrangements in the presence of weak and strong ligands. The 'spin only' magnetic moments of these complexes with weak and strong ligands, respectively, are

Let \(P=\left[a_{i j}\right]\) be a \(3 \times 3\) matrix and let \(Q=\left[b_{i j}\right]\) be a \(3 \times 3\) matrix,
where \(b_{i j}=2^{i+j} a_{i j}\) for \(1 \leq i, j \leq 3\).
If the determinant of \(P\) is 2 , then the determinant of the matrix \(Q\) is ___________ .

Read the following paragraph carefully and answer the given questions.
Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-neutrophils) and monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes. For determining the cause of allergy, the patient is exposed to or injected with very small doses of possible allergens, and the reactions studied. The use of drugs like anti-histamine, adrenalin and steroids quickly reduce the symptoms of allergy. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine. Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (magnetic resonance imaging) are very useful to detect cancers of the internal organs. Different species of Plasmodium (P. vivax, P. malaria and P. falciparum) are responsible for different types of malaria. Of these, malignant malaria caused by Plasmodium falciparum is the most serious one and can even be fatal.
Which one of the following drugs can not quickly reduce the symptoms of allergy?