1. Which equation gives the energy equivalent of a mass m?
A.
E = mc^2
B.
E = mv
C.
E = m/c^2
D.
E = c^2/m
Correct Answer:
E = mc^2
Explanation:
According to Einstein's mass-energy equivalence principle, the energy equivalent of mass m is E = mc^2, where c is the speed of light.
2. What is the approximate energy equivalent of 1 atomic mass unit (u)?
A.
9.315 MeV
B.
93.15 MeV
C.
931.5 MeV
D.
9315 MeV
Correct Answer:
931.5 MeV
Explanation:
Using E = mc^2, the energy equivalent of 1 u is approximately 931.5 MeV.
3. If a mass of 1 kg is completely converted into energy, which expression gives the energy produced?
A.
c joules
B.
c^2 joules
C.
1/c^2 joules
D.
2c^2 joules
Correct Answer:
c^2 joules
Explanation:
For m = 1 kg, Einstein's equation E = mc^2 becomes E = c^2 joules.
4. A mass defect of 0.01 u corresponds approximately to what amount of energy?
A.
0.09315 MeV
B.
0.9315 MeV
C.
9.315 MeV
D.
93.15 MeV
Correct Answer:
9.315 MeV
Explanation:
The energy equivalent is obtained by multiplying the mass defect by 931.5 MeV/u: 0.01 x 931.5 = 9.315 MeV.
5. When a mass defect occurs in a nuclear reaction, the missing mass is mainly converted into:
A.
Nuclear energy
B.
Electric charge
C.
Atomic number
D.
Nuclear volume
Correct Answer:
Nuclear energy
Explanation:
The mass defect is converted into energy according to E = delta m c^2.
6. If the mass converted into energy is doubled, the energy released will be:
A.
Halved
B.
Unchanged
C.
Doubled
D.
Quadrupled
Correct Answer:
Doubled
Explanation:
Since E = mc^2 and c is constant, energy is directly proportional to the converted mass.
7. A mass of 1 gram is completely converted into energy. What is the approximate energy produced?
A.
9 x 10^10 J
B.
9 x 10^11 J
C.
9 x 10^13 J
D.
9 x 10^16 J
Correct Answer:
9 x 10^13 J
Explanation:
For 1 gram, m = 10^-3 kg. Thus E = mc^2 = 10^-3 x (3 x 10^8)^2, which is approximately 9 x 10^13 J.
8. The energy equivalent of a mass defect of 2 u is approximately:
A.
465.75 MeV
B.
931.5 MeV
C.
1863 MeV
D.
3726 MeV
Correct Answer:
1863 MeV
Explanation:
Using 1 u = 931.5 MeV, the energy equivalent of 2 u is 2 x 931.5 = 1863 MeV.
9. In the equation E = mc^2, the symbol c represents:
A.
The speed of sound
B.
The speed of light in vacuum
C.
The speed of the nucleus
D.
The speed of an electron
Correct Answer:
The speed of light in vacuum
Explanation:
In mass-energy conversion, c is the speed of light in vacuum, approximately 3 x 10^8 m/s.
10. A mass defect of 0.001 u is equivalent to approximately:
A.
0.09315 MeV
B.
0.9315 MeV
C.
9.315 MeV
D.
93.15 MeV
Correct Answer:
0.9315 MeV
Explanation:
The converted energy is delta m x 931.5 MeV/u = 0.001 x 931.5 = 0.9315 MeV.
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