KVPY ans - 28-oct-10

KVPY QUESTION WITHANSWER(28-10-10)

1.

If tan 25° = x, then

tan 155  tan 115 is 1  tan 155  tan115

equal to : (A*) (C) Sol.

1 x2 2x 1 x2

(B)

2

1 x tan 25º = x

(D)

1 x2 2x 1 x2 1 x

2

tan 155 º  tan 115 º 1  tan 155 º tan 115 º

tan(180º 25º )  tan(90º 25º ) 1  tan(180º 25º ) tan(90º 25º )

=

 tan 25 º  cot 25 º

=

1  tan 25 º cot 25 º tan (180º  – ) = – tan  tan (90º + ) =  – cot 





=

2.

1 1 x2 x = 1 1 2x x

The intensity of scattered light depends on the wavelength wavelength of incident light ? (A)   4 (C) 

3.

 2

(B*)  (D) 

  –4   –2

The percentage of iron in a sample of haemoglobin was 0.34. If one haemoglobin molecule has 4 iron atoms, then its molecular weight is about

Sol.

(A) 41000.

(B) 16400.

(C*) 66000.

(D) 13200.

% of iron in haemoglobin = 4

molecular weight of iron  100 molecular weight of haemoglobi n

0.34 =

4  55.8  100 molecular weight of haemoglobi n

molecular weight of haemoglobin

 66000

4.

Synaptinemal complex is found associated with: (A*) paired meiotic chromosomes (B) lampbrush chromosomes (C) polytene chromosomes (D) mitotic chromosomes