用戶【pheobe1212】點評問題和點評內容

【評論主題】57.在X光管中,電子束打在actual focal spot size 3 mm寬,傾斜角度20°陽極上,其effective focal spot size為多少?(A)0.5 mm (B)1.0

【評論內容】當角度小的時候,sin(a θ) ≈ a sinθsin30° = 1/2sin20° ≈ sin30° x (2/3) = 1/33 mm x sin20° ≈ 1 mm

【評論主題】57.在X光管中,電子束打在actual focal spot size 3 mm寬,傾斜角度20°陽極上,其effective focal spot size為多少?(A)0.5 mm (B)1.0

【評論內容】當角度小的時候,sin(a θ) ≈ a sinθsin30° = 1/2sin20° ≈ sin30° x (2/3) = 1/33 mm x sin20° ≈ 1 mm