Identify the given parameters

The rated secondary current of the CT is $5\text{ A}$, and the pickup setting (tapping) is given as $150\%$ of the rated current.

$I_{rated} = 5\text{ A}, \text{ Tapping} = 150\% = 1.5$

Apply the pickup current formula

The pickup current ($I_{pickup}$) is calculated by multiplying the rated secondary current by the percentage tapping value expressed as a decimal.

$I_{pickup} = 5\text{ A} \times 1.5$

Calculate the final value

Performing the multiplication yields the pickup current required for relay operation.

$I_{pickup} = 7.5\text{ A}$