Microscope and Microscopy (Advanced)

CBSE Science. Optional Advanced level: total magnification, real size and field of view, resolution and resolving power, light, phase-contrast, fluorescence, TEM and SEM. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.

Open a printable sample sheet Cheat sheet: formulas and key points

Sample questions

Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.

Section A · multiple choice

1.
A microscope has a 5X eyepiece and a 15X objective. Its total magnification is:
1. 750X
2. 20X
3. 15X
4. 75X
Answer
(d) 75X
M = mₒ × mₑ = 15 × 5
2.
Under a total magnification of 2,000X, the image of a cell is 30 mm across. Its real size is: (Give the answer to 2 decimal places where needed.)
1. 1.5 µm
2. 60,000 µm
3. 15 µm
4. 150 µm
Answer
(c) 15 µm
real size = image ÷ M = 30 mm ÷ 2000 = 30,000 µm ÷ 2000
3.
At 40X total magnification the field of view is 5 mm across. Taking the field of view as inversely proportional to magnification, at 200X it is: (Give the answer to 2 decimal places where needed.)
1. 5 mm
2. 25 mm
3. 1 mm
4. 0.2 mm
Answer
(c) 1 mm
5 × 40 ÷ 200

Section B · short answer

4.
A student wants a total magnification of 100X with a 5X eyepiece. What objective should she use?
Answer
20X
100 ÷ 5
5.
A cheek cell's image measures 7.9 cm at a magnification of 80X. Find its real size in µm. (Give the answer to 2 decimal places where needed.)
Answer
987.5 µm
7.9 cm = 79,000 µm; ÷ 80

Section C · long answer

6.
A microscope has a 5X eyepiece and a 40X objective. (a) Find its total magnification. (b) At this setting the field of view is 1.8 mm and 3 cells fit across it. Estimate the size of one cell in µm. (c) How big does one cell's image look, in mm? (Give the answer to 2 decimal places where needed.)
Answer
(a) 200X; (b) 600 µm; (c) 120 mm
(a) 40 × 5; (b) 1,800 µm ÷ 3; (c) 600 µm × 200 ÷ 1,000

Fresh sheets for your child

In the app, every Microscope and Microscopy (Advanced) sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.

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