# IGCSE Physics Paper-1: Specimen Questions with Answers 25 - 26 of 149

## Question 25

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### Question

MCQ▾

If light enters glass, find angle of incidence ad refraction in the diagram below.

### Choices

Choice (4)
a.Angle of incident – 1, Angle of refraction – 3
b.Angle of incident – 2, Angle of refraction – 4
c.Angle of incident – 1, Angle of refraction – 4
d.Angle of incident – 2, Angle of refraction – 3

b.

### Explanation

Angle of incidence is a measure of deviation of something from “straight on”.

The angle of incidence is the angle between ray incidents on a surface and the line perpendicular to the surface at the point of incident called the normal.

Therefore angle 2 is incident angle.

Similarly, the angle between the reflected ray and the normal is known as the angle of reflection.

Therefore, angle 4 is angle of refraction

## Question 26

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### Question

MCQ▾

4 divers are there, 2 in sea water and 2 in fresh water. Which diver will face lowest pressure known that sea water is denser than fresh water?

Choice (4)
a.D
b.C
c.A
d.B

b.

### Explanation

Pressure in liquid we can define as

Where ρ = Density of liquid

g = Gravitational acceleration

h = Height above the point at which we measure the pressure

In this case density of fresh water is rarer than the sea water and height of diver C is less.

Thus on diver C is there the lowest pressure.