Question
The image shows an animal.
The length of the animal in the image is 36mm. The actual length of the animal is 12mm. What is the magnification of the image?
A ×0.3
B ×3
C ×43.2
D ×432
▶️Answer/Explanation
Ans B
The correct answer is B (×3), because :
Magnification = (original size) ÷ (actual size)
Magnification = 36 mm ÷ 12 mm
Magnification = 3
Question
Which formula is correct for calculations involving image size, actual size and magnification?
A) actual size = image size × magnification
B) image size = magnification × actual size
C) magnification = actual size ÷ image size
D) magnification = image size × actual size
▶️Answer/Explanation
Ans: B
The correct answer is B, because:
Magnification = (original image) ÷ (actual size)
Magnification size = (image size) ÷ (actual size)
Image size = Magnificcation × Actual size
Question
Which magnification formula is correct?
A magnification = actual size ÷ image size
B magnification = actual size + image size
C magnification = image size ÷ actual size
D magnification = image size × actual size
▶️Answer/Explanation
Ans: C
The correct answer is C, because :
Question
The cell shown in the diagram has been magnified 3000 times. The diagram is 21 mm wide.
A 21 mm
B \(\frac{21mm}{3000}\)
C \(21 mm \times 3000\)
D \(\frac{3000}{21mm}\)
▶️Answer/Explanation
B \(\frac{21mm}{3000}\)
The correct answer is B, because :
Magnification = (original size) ÷ (actual size)
3000 = (original size) ÷ (21 mm)
Original size = \(\frac{21mm}{3000}\)