Question

focal length of
u= -100
v = +25

2)u= -60
v= +30

3)u= -40
v= +40

4)u= -30
v= +60

u= -25
v= +100

please help in my project i am in 10th class please​

Answer 1

Formula for spherical mirrors
1/v + 1/u = 1/f


1. 1/25 - 1/100 = 3/100
f = 100/3 cm

2. 1/30 - 1/60 = 1/60
f = 60 cm

3. 1/40 - 1/40 = 0
f = 1/0 = Infinite (Plane mirror)

4. 1/60 - 1/30 = -1/60
f = -60 cm

5. 1/100 - 1/25 = -3/100
f = -100/3 cm


In case of lens
The formula will be
1/v - 1/u = 1/f



Mark as brainliest !

Answer 2

Answer:

1/ 25 - 1 /100=3/100

f=100/3

1/30 - 1/60 =1/60

f=60

1/40 - 1/40 =0

f=1/0

1/60 - 1/30=-1/60

1/100 - 1/25 = -3/100

f=-100/3 cm