Which of the following statements are correct?
A. The algebraic sum of potential drops around any closed loop is zero.
B. Metals have high resistivity.
C. The potentiometer is a device in which a condition of no current flow applies.
D. Kirchhoff's junction rule is based on conservation of charge.
E. Bending the wire changes the validity of Kirchhoff's junction rule.
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Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively, illuminate a metal of work function 0.5 eV. The ratio of the maximum KE of the emitted electrons will be :

Eg (energy band-gap) for silicon is greater than that for germanium. Therefore, it can be concluded that at room temperature:

A transformer with turns ratio \( \frac{N_1}{N_2} = \frac{100}{1} \) is connected to a 240 V ac supply. If the primary and secondary resistance are \( 1.0 \text{ k}\Omega \) and \( 1 \ \Omega \) respectively, then find the output power ?

The half life of a radioactive isotope of Iodine 131 is 8 days. Starting with 64 mg of the Iodine 131, the amount that disintegrates in 24 days is :

The potential of a charged spherical conductor of radius r is 20V. The potential at a point r/4 from its center is:

A light wave has a frequency of \( 4 \times 10^{14} \, \text{Hz} \). Find the difference in its wavelengths in alcohol of refractive index 1.35 and glass of refractive index 1.5 :

Read the passage given below and answer the question.
The transition elements which give the greatest number of oxidation states occur in or near the middle of the series. Manganese, for example, exhibits all the oxidation states from +2 to +7. The lesser number of oxidation states at extreme ends stems from either too few electrons to lose or share (Sc, Ti) on too many d-electrons (hence fewer orbitals available in which to share electrons with others) for higher valence (Cu, Zn). Thus early in the series scandium (II) is virtually unknown and titanium (IV) is more stable than Ti (III) or Ti (II). At the other end, the only oxidation state of zinc is +2 (no d electrons are involved). The maximum oxidation states of reasonable stability correspond in value to the sum of the s- and d-electrons upto manganese (\(TiO_2, VVO^+, CrVIO_4^{2-}, MnVIIO_4\)) followed by a rather abrupt decrease in stability of higher oxidation states, so that the typical species to follow are \(Fe^{II,III}, Co^{II,III}, Ni^{II}, Cu^{I,II}, Zn^{II}\).
The variability of oxidation states, a characteristic of transition elements, arises out of incomplete filling of d-orbitals in such a way that their oxidation states differ from each other by unity, e.g. \(V^{II}, V^{III}, V^{IV}, V^{V}\). This is in contrast with the variability of oxidation states of non transition elements where oxidation states normally differ by a unit of two.
An interesting feature in the variability of oxidation states of the d-block elements is noticed among the groups (groups 4 through 10). Although in the p-block, the lower oxidation states are favoured by the heavier members (due to inert pair effect), the opposite is true in the groups of d-block. For example, in group 6, Mo(VI) and W(VI) are found to be more stable than Cr(VI). The Cr(VI) in the form of dichromate in acidic medium is a strong oxidising agent, whereas \(MoO_3\) and \(WO_3\) are not.
Low oxidation states are found when a complex compound has ligands capable of \(\pi\)-acceptor character in addition to the \(\sigma\)-bonding. For example, in \(Ni(CO)_4\) and \(Fe(CO)_5\), the oxidation state of nickel and iron is zero.
The elements giving minimum number of oxidation states are in extreme left and right in 3d series.
This is because :

Last year, in a rat population of 600 rats, 600 new rats were added through reproduction in the current year to make a total population of 1200 rats.
Find the birth rate of this rat population.

Taylor and colleagues proved semiconservative nature of DNA through their experiments on Vicia Faba

The minimum value of the function \(f(x)=x^3+(10-x)^3\) occurs at :

Which of the following is not the salient feature of Human Genome Project (HGP)?

Match List - I with List - II.

LIST I (Disease)	LIST II (Causal organism)
A. Ascariasis	I. Salmonella typhi
B. Amoebiasis	II. Plasmodium vivax
C. Typhoid	III. Entamoeba histolytica
D. Malaria	IV. Ascaris

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