IIT MCQ

1. A beaker is completely filled with water at 4°C . It will overflow if : 

  

   (a) heated above 4°C 

   (b) cooled below 4°C 

   (c) both heated and cooled above and below 4°C              respectively 

   (d) none of the above 

 Answer: (c)  At 4°C , density of water is maximum . Therefore , density will decrease both above and below 4°C . Or volume will increase . 

2. Two plates charged to +q1 and +q2 ( q2 < q1 ) are brought closer to form a capacitor of capacitance C . The potential difference across the plates is : 

  (a) (q1 - q2 ) / 2C

  (b)  (q1 - q2 )/C 

  (c) (q1 - q2 )/4C

  (d) 2(q1 - q2 )/C 

Answer: (a)  

3. A wire carrying current I and other carrying 2I in the same direction produce a magnetic field of magnitude B at the mid point . What will be the field when 2I wire is switched off ?;

 (a) B/2 

 (b) 2B 

 (c) B 

 (d) 4B 

Answer: (c ) 

4. An object is placed at a distance equal to focal length of convex mirror . If the focal length of the mirror be f , then the distance of the image from the pole of the mirror is : 

 (a) less than f 

 (b) equal to f 

 (c) more than f 

 (d) infinity 

Answer: (a) 

5. At 0°C , the density of a gaseous oxide at 2 bar is same as that of nitrogen at 5 bar . The molecular mass of the oxide is : 

 (a) 70 

 (b) 140 

 (c) 28

 (d) 60 

Answer: (a) 

6. A pale yellow precipitate and a gas with pungent odour are formed on warming dilute hydrochloric acid with an aqueous solution containing : 

 (a) sulphate ion 

 (b) sulphide ion 

 (c) thiosulphate ion 

 (d) sulphite ion 

Answer: (c) 

7. Chloroplatinic acid is : 

 (a) monobasic 

 (b) dibasic 

 (c) tribasic 

 (d) tetrabasic 

Answer: (b) 

8. Borax structure contains : 

 

 (a) Two BO4 groups and two BO3 groups 

 (b) Four BO4 groups only 

 (c) Four BO3 groups only 

 (4) Three BO4 and one BO3 groups 

Answer: (a) 

9.  If the normals drawn at four concyclic points on a rectangular hyperbola xy = c^2 meet at the point (a,b) then the center of the circle has the coordinates 

(a) (a, b ) 

(b) ( 2a, 2b ) 

(c) ( a/2, b/2 ) 

(d) ( a/4, b/4 ) 

Answer: (c) 

10. A circle with fixed center (3h, 3k ) and of variable radius cuts the rectangular hyperbola x^2 - y^2 = 9a^2 at the points A, B ,C D. The locus of the centroid of the triangle ABC is given by : 

 

 (a) ( x - 2h ) ^2 - ( y - 2k ) ^2  = a^2 

 (b) ( x - h )^2 - (y - k )^2 = a^2 

 (c) x^2/h^2 - y^2/k^2 = a^2 

 (d) x^2/h^2 + y^2/k^2 =a^2 

Answer : (a)