10th science Refresher Course 4 Answer English Medium 

EVALUATION

I.  Choose the correct answer

1.  A magnet attracts _______

a) Wooden materials  

 b) any metal

c) Copper        

d) Iron and Steel

2.  One of the following is an example for a permanent magnet

a) Electromagnet          

b) Gunmetal   

c) Soft iron      

d) Neodymium

3. The south pole of a bar magnet and the north pole of a U-Shaped magnet will ____

a) Attract each other

b) Repel each other

c) Neither attract nor repel each other            

d) None of the above

4. The shape of the Earth’s magnetic fi ld resembles that of an imaginary _____

a) U-Shaped magnet

c)  Solenoid coil

b) Straight conductor carrying current

d) Bar magnet

5. MRI stands for _____

a) Magnetic Resonance Imaging                      

b) Magnetic Running Image

c)   Magnetic Radio Imaging                        

d) Magnetic Radar Imaging

6. A compass is used for _____

a) Plotting magnetic lines

c)  Navigation

b) Detection of magnetic fi ld

d) All of these

II. Fill in the blanks

1.  The magnetic strength is ______      at the poles.          

Answer : maximum

2.  A magnet has _____ magnetic poles.                                 

Answer :  two

3.  Magnets are used in _____           for generating electricity.                                                              

Answer : dynamos

4.  ______             are used to lift heavy iron pieces.

Answer : Electromagnets

5. A freely suspended bar magnet is always pointing along the ____ direction.

Answer :geographic north-south      

6.  Like poles of magnets repel while unlike poles _____      

Answer :attract

7.  The force of attraction of a magnet is ____ at the poles.

Answer :more

8.  Now a days, magnets are used to generate ______     in dynamos.                                    

Answer :current

9.  Magnets are used in computers in the storing devices such as hard disks.  They are used in _____ and ____ cards also.

Answer : Debit and Credit