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Study the following letter-number arrangement and answer the question given below :
B84CRM9PDKWFA2EJ7XUQHLTY6GSL
If the first half of the above arrangement is written in reverse order followed by the second half-written in reverse order, which letter/number will be eighteenth from left?

(a) Y
(b) K
(c) 7
(d) 6

Which of the following statements are correct regarding the given figure?
(i) The parts labelled as Q and R carry blood having low oxygen concentration.
(ii) The parts labelled as P, Q and R carry blood having low oxygen concentration.
(iii) The blood flows out of the heart through blood vessel Q when ventricle contracts.
(iv) The blood is flowing out of the heart through blood vessel Q when atria contract.


A (ii) and (iv) only
B (ii), (iii) and (iv) only
C (i), (ii) and (iii) only
D (i) and (iii) only

In a Drosophila, black eye colour is dominant over brown eye and allele for normal wings is dominant over allele of vestigial wing. Hybrid obtained in F₁ generation have black eye colour with normal wing. By selfing of F₁ hybrid, total 560 offspring were obtained in F₂ having four different genotypes. How many flies with black eyes and vestigial wings; and brown eyes with normal wings would be obtained? What would be their possible genotypes?


A105--- 210--- BBWw--- bbWw
B 105--- 105--- Bbww--- bbWw
C 315--- 35--- BbWw--- Bbww
D 100--- 150--- bbww--- BBww

An object is placed at a distance of 45 cm from a converging lens of focal length 30 cm. A convex mirror of radius of curvature 40 cm is to be placed on the other side of lens so that the object coincides with its image. Find the position of the mirror from the lens.

A 50 cm
B 60 cm
C 90 cm
D 30 cm

Fill in the blanks with most appropriate option.
Bio-gas is an excellent fuel as it contains up to 75% __(i)__ . It burns without smoke, leaves no residue like ash in wood. Its heating capacity is __(ii)__ . The slurry left behind is removed periodically and used as excellent manure, rich in __(iii)__and __(iv)__.

Which of the following statements are correct?
(i) The glass sheet in a solar cooker is responsible for green house effect.
(ii) Acid rain happens because earth’s atmosphere contains acids.
(iii) Biomass is a renewable source of energy.
(iv) Non-conventional sources of energy are nuclear, solar, biomass etc.
(v) Sun can be taken as inexhaustible source of energy.

A(i) and (iv) only
B (ii) and (iii) only
C (iii), (iv) and (v) only
D (i), (iii) and (v) only

A wire of resistance 4 Ω is used to wind a coil of radius 7 cm. The wire has a diameter of 1.4 mm and the specific resistance of its material is 2 × 10^-7 Ω m. The number of turns in the coil is

A 50
B 40
C 60
D 70

A wire of resistance 5 Ω is bent into a circular loop and the resistance between its diametrically opposite points is measured to be R. Now, it is stretched so that its length is increased by twice its original. Again, it is bent into a bigger circular loop and the resistance between its diametrically opposite points is measured to be R'. Then R : R' will be

A 1 : 4
B 9 : 1
C 1 : 9
D 1 : 1