Answer: The correct answer for the fill in the blank is 600
Explanation-
As per the question, the magnification of high power objective \((m_{o} )\) = 40x
Magnification of eye piece \((m_{e} )= 15x\)
Total magnification
\(m= m_{o} \times m_{e}\)
Putting the values of \(m_{o}\text{ and }m_e\)
= 40×15
= 600
Thus, total magnification= 600x
