A nucleus of mass 218 amu in free state decays to emit an α-particle. Kinetic energy of the α-particle emitted is 6.7 MeV. The recoil energy (in MeV) of the daughter nucleus is

(1) 1.0             

(2) 0.5

(3) 0.25           

(4) 0.125

Subtopic:  Types of Decay |
 64%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

C14 has half life 5700 years. At the end of 11400 years, the actual amount left is  

(1) 0.5 of original amount

(2) 0.25 of original amount

(3) 0.125 of original amount

(4) 0.0625 of original amount

Subtopic:  Radioactivity (OLD NCERT) |
 76%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Mean life of a radioactive sample is 100 seconds. Then its half life (in minutes) is

(1) 0.693               

(2) 1

(3) 10-4                 

(4) 1.155

Subtopic:  Radioactivity (OLD NCERT) |
 68%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

A86222B84210. In this reaction how many α and β particles are emitted 
(a) 6α, 3β          (b) 3α, 4β 
(c) 4α, 3β          (d) 3α, 6β  

Subtopic:  Types of Decay |
 82%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The phenomenon of radioactivity is 
(1) Exothermic change which increases or decreases with temperature

(2) Increases on applied pressure

(3) Nuclear process does not depend on external factors

(4) None of the above

Subtopic:  Radioactivity (OLD NCERT) |
 74%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

If half life of radium is 77 days. Its decay constant in day will be
(1) 3×10-13/day           

(2) 9×10-3/day

(3) 1×10-3/day             

(4) 6×10-3/day

Subtopic:  Radioactivity (OLD NCERT) |
 82%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

Consider two nuclei of the same radioactive nuclide. One of the nuclei was created in a supernova explosion 5 billion years ago. The other was created in a nuclear reactor 5 minutes ago. The probability of decay during the next time is 
(1) Different for each nuclei

(2) Nuclei created in explosion decays first

(3) Nuclei created in the reactor decays first

(4) Independent of the time of creation

Subtopic:  Radioactivity (OLD NCERT) |
 62%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

An α-particle of 5 MeV energy strikes with a nucleus of uranium at stationary at a scattering angle of 180o. The nearest distance up to which α-particle reaches the nucleus will be of the order of:
(1) 1 Å               

(2) 10-10 cm 

(3) 10-12 cm      

(4) 10-15 cm

Subtopic:  Types of Decay |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A neutron with velocity V strikes a stationary deuterium atom. Its kinetic energy changes by a factor of 
(1) 1516             

(2) 12

(3) 21               

(4) None of these

Subtopic:  Mass-Energy Equivalent |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

The sun radiates energy in all directions. The average radiations received on the earth surface from the sun is 1.4 kilowatt/m2.The average earth- sun distance is 1.5×1011 metres. The mass lost by the sun per day is
(1 day = 86400 seconds) 
(a) 4.4×109 kg          (b) 7.6×1014 kg
(c) 3.8×1012 kg         (d) 3.8×1014 kg

Subtopic:  Mass-Energy Equivalent |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch