Mass Energy Equivalence

Q. The nuclear structures of some atoms are as follows-
$\left(i\right)8p+2n$ $\left(ii\right)8p+22n$
$\left(iii\right)18p+22n$ $\left(iv\right)20p+20n$
from these isobaric are-

1. $\left(i\right)$ and $\left(iii\right)$
2. $\left(iii\right)$ and $\left(iv\right)$
3. $\left(i\right)$ and $\left(ii\right)$
4. $\left(i\right)$ and $\left(iv\right)$

Q. 1 g of hydrogen is converted into 0.993 g of helium in a thermonuclear reaction. The energy released

1. $63\times {10}^{7}J$
2. $63\times {10}^{20}J$
3. $63\times {10}^{10}J$
4. $63\times {10}^{14}J$

Q. A person is advised to wear spectacles with concave lenses. What type of defect of vision is he suffering from ?