Answer:
5 x 10⁻⁵ T 
Step-by-step explanation:
Magnetic field at a point d distance away from a current carrying wire having current of I 
B = 10⁻⁷ x 2I / d 
Here magnetic field due to current of 20 A 
B₁ = 10⁻⁷ x 2 x 20 / 10 x 10⁻²
= 4 x 10⁻⁵ T .
Here magnetic field due to current of 5 A 
B₂ = 10⁻⁷ x 2 x 5 / 10 x 10⁻²
= 10⁻⁵ T .
These magnetic fields are acting in the same direction 
Total magnetic field 
B = B₁ + B₂
= 4 x 10⁻⁵ + 10⁻⁵ = 5 x 10⁻⁵ T .