In the given circuit parameter k is positive and power dissipated

In the given circuit parameter k is positive and power dissipated in 2 Ω resistor is 12.5W. The value of k is __________.

Power dissipated in 2Ω P = I²R
12.5 = I² × 2
I = 2.5 Amp
V₀ = I × 2 = 2.5 × 2
V₀ = 5 volt
Apply KCL,
I + KV₀ = 5
2.5 + K × 5 = 5

K = 0.5