Assume that an electric field \( (20\hat{i}) \text{ V m}^{-1} \) exists in the region of space. If \( V_0 \) is the potential at the origin and \( V_A \) is the potential at \( x = 1 \text{ m} \), then the potential difference \( V_A - V_0 \) is :

For transistor action, which of the following statements are correct
A. Both the emitter junction as well as the collector junction are forward biased.
B. The base region must be very thin and lightly dopped.
C. Base, emitter and collector should have same doping concentration.
D. The emitter junction is forward and collector junction is reverse bias.
Choose the correct answer from the options given below:

In which of the following cases emf would be induced-

A sample of HCl gas is placed in an electric field of \(3 \times 10^4 \mathrm{~N} \mathrm{C}^{-1}\). The dipole moment of each HCl molecule is \(6 \times 10^{-30} \mathrm{C} \mathrm{m}\). The maximum torque that can act on this molecule is :

Where is donor energy level located?

The critical angle of incidence \( i_c \) for a ray incident from a denser to a rarer medium, is that angle for which

Electric potential on an equitorial plane of an electric dipole is taken as zero. This is based on

Name the reaction when carboxyclic acids having an a -hydrogen are halogenated at the a-position on treatment with chlorine in the presence of a small amount of red phosphorus.

The electric field in a copper wire of cross-sectional area \( 4 \, mm^2 \) carrying a current of 1 A and having electrical conductivity of \( 6.25 \times 10^7 \, Sm^{-1} \) is

Read the passage carefully and answer the questions
Sodium dichromate \(Na _2 Cr _2 O _7\) and Potassium dichromate \(K _2 Cr _2 O _7\) are strong oxidizing agents; in acidic solution, its oxidising action can be represented as follows :
\(Cr _2 O _7^{2-}+14 H ^{+}+6 e^{-} \rightarrow 2 Cr ^{3+}+7 H _2 O \left( E ^{\circ}=1.33 V\right)\)
The chromates and dichromates are interconvertible in aqueous solution depending upon pH of the solution.
The chromate ion is tetrahedral whereas the dichromate ion consists of two tetrahedra sharing one corner with \(Cr - O - Cr\) bond angle of \(126^{\circ}\)
Potassium permanganate is prepared by fusion of \(MnO _2\) with an alkali metal hydroxide and an oxidising agent like \(KNO _3\).
This produces the dark green \(K _2 MnO _4\) which disproportionates in a neutral or acidic solution to give permanganate. It is a strong oxidizing agent. Hydrogen ion concentration of the solution plays 
an important part in the reduction of permanganate to manganate, manganese dioxide and manganese(II) salt.
Potassium permanganate forms dark purple (almost black) crystals which are isostructural with those of \(KClO _4\).
The salt is not very soluble in water \((6.4 g / 100 g\) of water at 293 K ), but when heated it decomposes at 513 K.
The number of moles of KMnO₄ required to react with one mole of sulphide ion in acidic solution is

\(^{70}Yb^{2+}\) and \(^{71}Lu^{3+}\) Lanthanoid ions are..........

A simple random sample consists of four observations 1, 3, 5, 7. The point estimate of population standard deviation is :

The electronic configuration of the last three orbitals in cerium (At. No. 58) in ground state is: