10th science Refresher Course 3 Answer English Medium - ELECTRIC CHARGE AND ELECTRIC CURRENT

EVALUATION

I. CHOOSE THE BEST ANSWER

1. When an ebonite rod is rubbed with fur, the charge acquired by the fur is __________

(b) Positive

(a) negative

(c) Partly positive and partly negative                

(d) None of these 

2.  Which of the following should a simple circuit have?

(b) Energy Source, Wire, Switch

(d) Battery, Wire, Switch

(a) Energy Source, Battery, Resistor.

(c) Energy Source, Wire, Resistor 

3.  Fuse is __________________

(a) a switch

(b) a wire with low resistance

(c) a wire with high resistance       

(d) a protective device

4.  The process of depositing a layer of one metal over the surface of another metal by pass- ing electric current is called _____________

(b) Electroplating

(a) Electrolysis

(c) Chemical effect of current

(d) Heating effect of current

5.    In which circuit sum of each components will be the voltage drawn from the source? 

(a)  Series Circuit    

(b) Parallel Circuit      

(c) Simple Circuit     

(d) None of these

6.   In an electrolyte the current is due to the fl  w of

a) electrons

b) positive ions

c) both (a) and (b)

d) neither (a) nor (b)

7.   Electroplating is an example for

a) heating effect

b) chemical effect

c) fl  wing effect

d) magnetic effect

8.  Resistance of a wire depends on

a) temperature

b) geometry

c) nature of material

d) all of the above

II. FILL IN THE BLANKS: -

1.  The body which has lost electrons becomes___________________                               

Answer :  positive

2.  A device that stores electricity from chemical cells is ____________________               

Answer :  battery

3.  A fuse (consists) has ___________________________, ______________________ 

Answer :  high resistivity  , low melting point

4.  ____________________________ has a thin metal lic filament that melts and breaks the connection when the circuit is overheated.

Answer :   Fuse wire 

5.  Th ee bulbs are connected end to end from the battery.  Th s connection is called ______

Answer :  series connection

III. TRUE OR FALSE: -

1. In this series circuit, charges (electrons) from the battery have only one path to travel. 

Answer :  True

2.  In parallel circuit, current remains the same in all components.

Answer :   False

3.  Water can conduct electricity.

Answer :  True

4.   A charged body induces an opposite charge on an uncharged body when they are brought near.

Answer :  True

5.  In Parallel connection, if one component breaks down, the whole circuit will function. except the break down. 

Answer :   True

V.   Answer the following:

1.  Rubbing a plastic comb on hair makes the comb get – 0.4C.

(a) Find which material has lost electron and which one gained it.

• Hair has lost electron, comb gain electron

(b) Find how many electrons are transferred in this process.

2. Name any two appliances which work under the principle of

a. Heating effect of electric current

• Electric heater, Electric fuse

b. Magnetic effect of electric current

• Motor, Electric bell

c. Chemical effect of electric current

• i) Changes in solutin colour
• ii) Deposition of metel of electrode