Photo AI
4 (a) (i) Figure 4 shows two light rays hitting a glass lens - Edexcel - GCSE Physics - Question 4 - 2020 - Paper 1
Question 4
4 (a) (i) Figure 4 shows two light rays hitting a glass lens. On Figure 4, draw the two light rays after they leave this lens. (ii) Figure 5 shows two light rays h... show full transcript
Worked Solution & Example Answer:4 (a) (i) Figure 4 shows two light rays hitting a glass lens - Edexcel - GCSE Physics - Question 4 - 2020 - Paper 1
Step 1
4 (a) (i) Draw the light rays after they leave the lens.
Answer
To draw the light rays after they exit the lens, begin by indicating two rays: one parallel to the principal axis that diverges outwards as if emanating from the focal point on the opposite side, and the second ray that passes through the center of the lens, which continues in a straight path. The result should show rays diverging from the lens.
Step 2
4 (a) (ii) Draw the light rays after they leave the lens.
Answer
For this lens, draw a ray that approaches the lens parallel to the principal axis, which will converge after passing through the lens towards the focal point on the other side. The second ray should come through the focal point on the same side as it approaches the lens and continue in a straight path once it exits the lens.
Step 3
4 (a) (iii) Calculate the power of the lens.
Answer
To calculate the power of the lens, first convert the focal length from centimeters to meters:
( 25 \text{ cm} = 0.25 \text{ m} ). Next, use the formula for power in diopters:
[ \text{Power} = \frac{1}{\text{Focal Length}} = \frac{1}{0.25} = 4 , \text{diopters} ] Therefore, the power of the lens is 4 diopters.
Step 4
4 (b) (i) Determine the time when P and Q were at the same temperature.
Answer
To find the point where the temperatures of balls P and Q are the same, locate the intersection point of the two temperature curves on the graph in Figure 7. The time corresponding to this intersection is around 11 to 13 minutes. Thus, one can conclude that P and Q were at the same temperature at approximately 12 minutes.