[填空题]
(a) Suppose for a coqsecr h ) 7,epqz74t73p17mfcu 2psrznventional X-ray image+5ww0:0b ecki 4md.rx ai7jxn that the X-ray beam consists of parallel rays. What would be the magnificati+50x kcxb7nejw4.ramid 0 i:won of the image? a the magnification is
(b) Suppose, instead, the X-rays come from a point source (as in Fig. Below) that is 15 $cm$ in front of a human body 25 $cm$ thick, and the film is pressed against the person’s back. Determine and discuss the range of magnifications that results. $m_1$ = the magnification is