IJSo Solutions 23-10-10..

IJSO QUESTION WITHANSWER (23-10-10) 1.

Sol.

2.

The equation 8x + 4 = 4x + 2x + 2 has (A) no real solutions (B) one real solution (C*) two real solutions (D) three real solutions 8x + 4 = 4x + 2x + 2 23x + 4 = 22x + 4 × 2x Let 2x = y y3 + 4 = y2 + 4y y3  – y2  – 4y + 4 = 0 y2 (y  – 1)  – 4(y  – 1) = 0 (y2  – 4)(y  – 1) = 0 y = 2,  –2, 1 2x = 2, x=1 2x =  – 2, that is not possible 2x = 1 x=0 two real solution for x

B2 =

 0I2

2





2r 2r Net magnetic field at centre  0I11  I  B = B 1  – B2 =  – 0 2  2 2r  2r 2r 2r 0

B= 3.

4 r 2

(I11 – I22 ) = 0

In the balanced chemical reaction a, b, c and d respectively correspond to O13 –  a1 –  bH         cH2O  d 2

Sol.

(A*) 5,6,3,6 (B) 5,3,6,3 (C) 3,5,3,6 (D) 5,6,5,5 First remove a, b, c and d and balance the equation by ion electron method. O13 –  1 –  H        H2O   2

on splitting above equation into half reactions. Oxidation half reaction :

Any two ends of a circular conducting wire are connected by a cell. The magnetic field at the centre O is:

I

 –

     I2

 2I –1        I2 + 2e –

- - - - (i)

Reduction half reaction IO

1 –

IO

1 –

3

3

(A)

2 2  o (i1  i2 )

2r (C*) zero

(B)

    

I

2

I

    

2

+ 3H2O

O13 –  6H  5e –         2  3H2O - - - - (ii)

o (i1  i2 )

2r (D) None of these

2I –        I2 + 2e –

---

- (i) × 5

Sol.

i

1 –

O3  6H  5e         2  3H2O

2

i

2O13 –

1

O

R1  R2

I1  2 1  but I  so 2 I2  1 R I11 = I22 ...(i) Magnetic field at centre due to current I1  0I1   . ( here N = 1 )  1 O B2 = 2r 2r 2r Magnetic field due to current I2 1

---



 12H        12 2  6H2O

so net balanced equation O13 –  51 –  6H        6 2  3H2O

Then the resistance will will be in the ratio of the and 2

1 –

 10 

- (ii) × 2

Let the length 1 and 2 1

 –

4.

Sickle cell anaemia is disease in which patient suffering from a disorder of respiration and transportation system.This disease is known as (A) Metabolic disorder (B*) Genetic disorder (C) Degenerative disorder (D) Pathogenic disorder