Sound of Music

Sound of Music

Learning check!

#5

1.Which lens would make the best magnifying

glass ?A. Diverging, long focal length

B. Converging, long focal length

C. Diverging short focal length

D. Converging, short focal length

2.Real is positive means

A. Diverging lenses have negative focal lengths

B. Diverging lenses never produce real images

C. Converging lenses always produce real images

D. Converging lenses only produce real images from close up objects

3. 1/u + 1/v = 1/f

A. u = image distance

B. v =object distance

C. v = image distance

D. f = u + v

4.Which does NOT apply to the power of a lens

A. Measured in m-1

B. 1/f

C. Measured in D D. Always positive

5.A diverging lens CAN produce a real image if

A. It has a high power

B. The object is virtual

C. The object is closer than the focal length

D. The image is diminished

6.u =4cm, v = 6cm, f =?

A. 2.4cm B. 5cm

C. 3cm D. 10cm

7.u=3cm, v=-4cm, f= ?

A. 0.83cm B. 12cm

C. –12cm D. –0.83cm

8.The lens formula applies to

A. Thin mirrors B. All lenses

C. Thin lenses D. Octopus eyes

9.This object is placed 4cm from a converging lens of

focal length 6cm. Its image is

A. B.

C.

D.

10.Your favourite physics teacher’s eyesight has deteriorated from –2.25D to

–2.50D in 5 years. What is the rate of change of focal length in mmyr-1 ?

A.-0.0089 B 11.25

C. 0.0089 D. 1.25

11.Which has the longest focal length?

A. Diverging lens, red light

B. Converging, lens blue light

C. Diverging lens blue light

D. Converging, lens red light

12.Penguin eyes are more powerful

A. On land B. In water

C. In space D. In a pile of fish guts

Think – more powerful means f has decreased