Magnification

A student viewed a section of a leaf using a microscope.

The student measured the length of one of the palisade cells.

The cell image measured 28 mm in length when viewed at a magnification of ×400

Calculate the real length of the palisade cell in millimetres (mm).

• 0.07

• 0.08

• 70

• 700

Answer explanation

28/400

A scientist observed a cell using an electron microscope.

The size of the image was 25 mm.

The magnification was × 100 000

Calculate the real size of the cell in micrometres.

• 0.00025

• 25

• 0.25

• 0.75

Answer explanation

25/100 000

then divide by 1000 to convert to micrometres

 

A student drew a cell. It was 112mm long.

The real length of the cell was 280 micrometres (µm).

Calculate the magnification.

• 0.004

• 400

• 112,000

• 4000

Answer explanation

Convert 112 to micrometres (mutiply by 1000)

Then divide 112 000 by 280

One muscle cell was 0.05 mm wide.

When viewed using a microscope the image of the muscle cell was 2 mm wide.

Calculate the magnification used to view the cell.

• x400

• x40

• x4

• x4000

Answer explanation

2/0.05

The average diameter of a real red blood cell is 0.008 millimetres. On a photograph, the diameter of the red blood cell is 100 millimetres.

Use the formula to calculate the magnification of the photograph.

• 12500

• 125

• 0.00125

• 12.5

Answer explanation

100/0.008