X SA I TEST CHEM REACTION, ELECTRICITY, CONTROL & COORDINATION

X TEST – SCIENCE- CHEMICAL REACTION, ELECTRICITY, CONTROL & COORDINATION               M.M: 40

1.       [1]Define  electric  circuit.   Distinguish between open  and  closed  circuit.                                       

2.       [1] What  is meant by skeletal  equation ?                                                                                                

3.       [2]What  is a redox  reaction?   Write  down a chemical  equation representing it.           

4.       [3]Ram has  met  with  an accident after  that  he lost the  capacity to                                                

(i)      walk  in straight line         (ii)     smell  anything           (iii)    does  not feel full after  eating

Which  part  of brain  is damaged in each  case.

5.       [3]Name  the hormone secreted by ovary,  testes  and  adrenal glands.  Write  a function of each  hormone.

6.       [1,1] (a)     What  material is used  in making the filament of an electric  bulb  ?                                  

                   (b)     Name  the characteristics which  make  it suitable for this.

7.       [2] Differentiate overloading and  short  circuiting.                                                                        

8.       [2] Mention the components of the transport system in highly  organized plants.  State the functions of these  components.

9.       [2] What  is meant by thermal decomposition reaction ?  Explain  with  an example.                 

10.    [2] An aluminium can is used  to store Ferrous sulphate solution. It is observed that in few days  holes  appeared in the can.   Explain  the observation and  write  chemical  equation to support your  answer.

11.    [3] A piece of wire of resistance 20Wis drawn out so that its length  is increased to twice its original length.  Calculate the resistance of the wire  in the new  situation.

12.    [3] (a)     What  is the total  resistance of n resistors each of resistance ‘R’ connected in :             

                (i)      Series  (ii)     Parallel

13.     [3] Name  the hormone secreted by thyroid gland.  Write its function.  Why is it important for us to have  iodised salt in our  diet ?

14.    [3]How  does  feed-back mechanism regulate the hormone secretion ?                                         

15.    [3] Give  three  differences between displacement and  double displacement reaction.               

16.    [5]Four  metals  A,B,C and  D are inturn added to the following solutions one by one.   The observations made are tabulated below.

Metal	Iron (II) sulphate	Copper (II) Sulphate	Zinc sulphate	Silver nitrate
A	No reaction	Displacement	-	-
B	Displacement	-	No reaction	-
C	No reaction	No reaction	No reaction	Displacement
D	No reaction	No reaction	No reaction	No reaction

Answer the following questions based  on the above  information.

 (i)     Which  is the most  active  metal  and  why  ?

(ii)     What  would be observed if B is added to a solution of copper sulphate and  why.

(iii)    Arrange the metals  A,B,C and  D in order of increasing reactivity.

(iv)    Container of which  metal  can  be used  to store  both  Zinc sulphate solution and silver nitrate solution.

(v)     Which  of the above  solutions can be easily stored in a container made up  of any of these  metals.