A telescope has an objective of focal length \(3 0 ~ c m\) and an eyepiece of focal length \(3 . 0 ~ c m\). It is focused on a scale distant 2.0 m . For seeing with relaxed eye, the separation between the objective and eyepiece would be:

Identify the correct statement(s) from the following Resistivity (\( \rho \)) versus Temperature (T) graphs :

(A) Graph (i), shows \(\rho\) versus \(T\) variation for Copper
(B) Graph (ii), shows \(\rho\) versus \(T\) variation for Silicon
(C) Graph (iii), shows \(\rho\) versus \(T\) variation for semiconductor
(D) Graph (iii), shows \(\rho\) versus T variation for Nichrome
Choose the correct answer from the options given below :

A bar magnet of magnetic moment \(M_1\) is axially cut into two equal parts. If these two pieces are arranged perpendicular to each other in the shape of L, the resultant magnetic moment becomes \(M_2\), then the value of \(\frac{ M _1}{ M _2}\) is :

An object is placed at 5 cm in front of a concave mirror with a radius of curvature of 20 cm. The distance of the image from mirror and its nature are

Match List-I with List-II

List-I (Electromagnetic waves)	List-II (Wavelength range)
(A) X-rays	(I) 1 mm to 700 nm
(B) Radio waves	(II) 0.1 m to 1 mm
(C) Infrared waves	(III) 1 nm to \( 10^{-3} \) nm
(D) Microwaves	(IV) >0.1 m

Choose the correct answer from the options given below:

A uniform electric field of 20 V m -1 exists in the vertically downward direction. What will be the increase in the electric potential as one goes up through a height of 60 cm?

A 10 V battery of negligible internal resistance is connected with a 200 V battery and a set of parallel resistances as shown in the figure. The value of current in the circuit.

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 ( \(Ti ^{I V} O _2, V^V O _2^{+}, Cr ^{V I} O _4^{2-}\), \(Mn ^{\text {VII }} O _4\) ) followed by a rather abrupt decrease in stability of higher oxidation states, so that the typical species to follow are \(Fe ^{I I, I I I}, Co ^{I I, I I I}, Ni ^{I I}, Cu ^{I, I I}, Zn ^{I I}\).
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. \(V ^{I I}, V^{I I I}, V^{I V}, V^V\). 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 dblock. 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.
Which amongst the following is a better oxidising agent than other ?

The total cost of producing \(x\) generators is given by
\(TC =x^3-60 x^2+1500 x+2000\)
The Marginal Cost \(( MC )\), when \(x=10\) units is:

When electric current is passed through acidified water, 448 mL of hydrogen gas at STP is collected at the cathode in 965 seconds. The current passed in amperes is :

Match List I with List II.

LIST I (Name of the organism)	LIST II (Chromosome number in a meiocyte)
A. Rat	I. \(38\)
B. Dog	II. \(42\)
C. Cat	III. \(1260\)
D. Ophioglossum	IV. \(78\)

Choose the correct answer from the options given below:

A closed circuit in the form of a regular hexagon of side a carries a current I. What is the magnetic field at the centre of the hexagon?

Read the passage carefully and answer the given questions.
Recombinant DNA Technology Asexual reproduction preserves the genetic information, while sexual reproduction permits variation. Traditional hybridization procedures used in plants and animals breeding very often lead to inclusion and multiplication of undesirable genes along with the desired genes. The techniques of genetic engineering, which include creation of recombinant DNA, use of gene cloning and gene transfer, overcome this limitation and allow us to isolate and introduce only one or a set of desirable genes without introducing genes into the target organism.
In Recombinant DNA Technology, what is the role of the "selectable marker gene"?