Spherical mirrors Chapter 3

Question 1

Describe a concave mirror

Answer 1

Reflecting surface caves in at the centre

Question 2

Describe a convex mirror

Answer 2

Reflecting surface bulges out in the centre

Question 3

Why are they called spherical mirrors

Answer 3

Mirrors are taken from the surface of a sphere

Question 4

What is P of a spherical mirror

Answer 4

Pole - centre of the mirror

Question 5

What is C of a spherical mirror

Answer 5

Centre of curvature - centre of the sphere from which the mirror is made.

Question 6

What is F of a spherical mirror

Answer 6

Focus - Halfway point between C and P

Question 7

What is f of a spherical mirror

Answer 7

Focal length - Distance from f to P

Question 8

What is the line that joins P to C called

Answer 8

The principal axis

Question 9

Where is the normal in a concave mirror

Answer 9

The normal is at the point of incidence joined to the centre of curvature of the mirror

Question 10

Where is a ray that strikes the Pole reflected for a concave mirror

Answer 10

Reflected at an equal angle to the principal axis

Question 11

Where is a ray that passes through C reflected for a concave mirror

Answer 11

Back along it’s own path

Question 12

Where is a ray that comes into mirror parallel to axis reflected for a concave mirror

Answer 12

Reflected through the focus

Question 13

Explain a real image

Answer 13

Formed by the actual intersection of light rays - can be formed on a screen

Question 14

Explain a virtual image

Answer 14

Formed by the apparent intersection of light rays - can never be formed on a screen

Question 15

For a concave mirror when is an image real or virtual

Answer 15

Object outside the focus- image is real and in front of mirror
Object at focus or inside- image is virtual and behind the mirror

Question 16

When will an image be same size or different size to object

Answer 16

Image will be a different size unless object is at the centre of curvature

Question 17

Describe an image formed in a concave mirror when object is at C

Answer 17

real, same size, inverted

Question 18

Describe an image formed in a concave mirror when object is between C and F

Answer 18

real, magnified, inverted

Question 19

Describe an image formed in a concave mirror when object is at F

Answer 19

Blindspot

Question 20

Describe an image formed in a concave mirror when object is Inside F

Answer 20

virtual, magnified, upright

Question 21

Describe an image formed in a concave mirror when object is outside C

Answer 21

real, diminished, inverted

Question 22

Describe an image if an object is a large distance from a mirror

Answer 22

Image is real and at the focus

Question 23

What is the formula for magnification

Answer 23

height of image/height of object or v/u

Question 24

What is the formula to locate a real image

Answer 24

1/u + 1/v = 1/f

Question 25

What is the formula to locate a virtual image

Answer 25

1/u - 1/v = -1/f

Question 26

What are u and v in formulae

Answer 26

u - Distance from object to mirror

v - distance from image to mirror

Question 27

Give uses of a convex mirror

Answer 27

Cars, shops to see whole shop

Question 28

Use of a concave mirror

Answer 28

shaving mirror, headlights

Question 29

How is an approximate value for the focal length found in the experiment to measure the focal length of a concave mirror and why should you do this.

Answer 29

Image of a distant object is focused on a screen and measure the distance from the screen to the mirror.

This avoids placing the object near or inside f

Question 30

How is graph drawn of results from the experiment to measure the focal length of a concave mirror

Answer 30

find values for 1/u and 1/v and graph against each other. Then draw straight line through them.