Due to hybridisation________hybrid orbitals are formed .

Explanation

**Step-by-Step Solution:**

1. **Understanding Hybridization**: Hybridization is a process in which atomic orbitals mix to form new hybrid orbitals. These hybrid orbitals have different shapes and energies compared to the original atomic orbitals.

2. **Formation of Hybrid Orbitals**: During hybridization, the atomic orbitals involved (such as s, p, and sometimes d orbitals) combine to form new orbitals that are degenerate and equivalent. This means all hybrid orbitals produced have the same energy level.

3. **Example of Methane (CH₄)**: Consider the carbon atom in methane. The electronic configuration of carbon is 1s² 2s² 2p². To form four bonds in methane, one of the 2s electrons is promoted to the 2p orbital, resulting in four unpaired electrons.

4. **Mixing of Orbitals**: In methane, the 1s orbital of carbon mixes with three 2p orbitals to form four equivalent sp³ hybrid orbitals. These sp³ hybrid orbitals are degenerate, meaning they all have the same energy.

5. **Conclusion**: Therefore, due to hybridization, degenerate and equivalent hybrid orbitals are formed. This process allows atoms to form stable bonds by achieving a lower energy state.

**Final Answer**: Due to hybridization, **degenerate and equivalent** hybrid orbitals are formed.

---