GENERAL KNOWLEDGE

Detailed explanation-1: -The high temperature provides them with enough energy to overcome their mutual electrical repulsion. Once the nuclei come within a very close range of each other, the attractive nuclear force between them will outweigh the electrical repulsion and allow them to fuse.

Detailed explanation-2: -To make the fusion possible, a high temperature of approximately 107K and high pressure is required. Due to thermal agitations both nuclei acquire sufficient kinetic energy at such a high temperature so as to overcome the force of repulsion between them when they approach each other and so they get fused.

Detailed explanation-3: -A long-recognized drawback of fusion energy is neutron radiation damage to exposed materials, causing swelling, embrittlement and fatigue.

Detailed explanation-4: -You are correct that fusion takes place at high pressure in the core of the Sun, and not actually in the surrounding vacuum; gravity is what holds the plasma together.