The formula for Electric Field Strength:
E = Q /(4πε₀r²)
Note:
1 /(4πε₀) = k = 8.99 10⁹ Nm²/C²
Q = 6 μC = 6 10⁻⁶ C. r = 0.5m
E = kQ / r²
E = (8.99 10⁹ 6 10⁻⁶) /(0.5²) Use a calculator
E = 215.6 10³ N/C
Electric field strength = 215 600 N/C.
I hope this helps.
