## Monday, November 29, 2010

### SPM tips ~ paper 2 ( light )

Diagram 9.1 and Diagram 9.2 show light rays from two identical objects passing through two identical convex lenses. Both lenses produce real images. F is the focal point for the lens.
Rajah 9.1 dan Rajah 9.2 menunjukkan sinar cahaya dari dua objek yang serupa melalui dua kanta yang serupa. Kedua-dua kanta tersebut menghasilkan imej nyata. F adalah titik fokus untuk kanta tersebut.

(a)
(i)
Name the phenomenon involved. [1 mark]
Namakan fenomena yang terlibat. [1 markah]

Hits for solving the problem :
Refraction of light is the bending of light ray at the boundary as it travels from one medium to another.
Reflection of light occurs when the light ray strike the surface of mirror.

ii)
Observe Diagram 9.1 and Diagram 9.2. Compare the object distance, the image distance, the size of the image and the power of the lens. Relate the size of the image with the object distance. [5 marks]

Perhatikan Rajah 9.1 dan Rajah 9.2. Bandingkan jarak objek, jarak imej, saiz imej dan kuasa kanta. Hubungkaitkan saiz imej dengan jarak objek. [5 markah]

Hits for solving the problem :
• Pay attention to the marks allocated. the marks usually indicates the number of points required.
1. Compare the object distance,
2. Compare the image distance,
3. Compare the size of the image
4. Compare the power of the lens.
5. Relate the size of the image with the object distance.

(b)
Diagram 9.3 shows the structure of a simple camera.
Rajah 9.3 menunjukkan struktur sebuah kamera ringkas.

(i)
Explain how the camera is able to capture the image of a distant object. [3 marks]
Terangkan bagaimana kamera boleh merakam imej suatu objek jauh. [3 markah]

Hits for solving the problem :
• Pay attention to the marks allocated , the marks usually indicates the number of points required

(ii)
State the range of the object distance where the image formed is sharp. [1 mark]
Nyatakan julat jarak objek bagi kedudukan imej yang tajam. [1markah]

(c)
A student is given two convex lenses, R and S. The focal length for R and S are 20 cm and 5 cm respectively. Suggest and explain how to build a microscope which produces a sharp and magnified image based on the following aspects:

Seorang pelajar diberi dua kanta cembung R dan S. Panjang fokus untuk R dan S adalah 20 cm dan 5 cm masing-masing. Cadang dan terangkan bagaimana anda membina sebuah mikroskop yang menghasilkan imej yang tajam dan dibesarkan berdasarkan aspek-aspek berikut:

Hits for solving the problem :
Underline the important information given in the question, such as focal length for each lens, build a microscope...

(i)
Arrangement of lenses
Susunan kanta

(ii)
Position of object
Kedudukan objek

(iii)
Position of the first image
Kedudukan imej pertama

(iv)
Distance between the two lenses
Jarak antara kedua-dua kanta

(d)
Suggest two modifications that need to be done to the microscope to produce a bigger final image. [2 marks]

Cadangkan dua ubahsuaian yang perlu dibuat pada mikroskop untuk menghasilkan imej akhir yang besar .[2 markah]

Hits for solving the problem :
M= Mo x Me

Anonymous said...

microscopes use lenses to bend an image so that it appears bigger.

Anonymous said...