Home Physics Atoms and Nuclei Radioactivity The half life of a radioactive substance is …
Physics Atoms and Nuclei Radioactivity Single Correct MCQ
Published on: August 21, 2026

The half life of a radioactive substance is 20 minutes. In how much time, the activity of substance drops to of its initial value?

A
60 minutes
B
80 minutes
C
20 minutes
D
40 minutes

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The correct answer is:

                    

                


                

                    
 , n = 4



                


                
                
                
                

                    
                    
                    
                        
                            
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