Question

Fusion processes, like combining two deuterons to form a $$He$$ nucleus are impossible at ordinary temperatures and pressure. The reasons for this can be traced to the fact:

Answer 1

Correct option is B. nuclei are positively charged
Two deuteron can combine to form $$He$$ atom when their nuclei come close to nuclear range where electrostatic repulsive force between positively charged deuterons does not act. The electrostatic force increases very high on decreasing their distance.
$$\left( \because F\propto \cfrac { 1 }{ { r }^{ 2 } } \right) $$
To overcome this electrostatic repulsive force nuclei need very high temperature and pressure. Hence to combine two nuclei, they must reach closer of the range of where nuclear force acts and electrostatic repulsive force does not act verifies the answer (a) and (b)