Question

Two thin lenses of focal length +10 cm and -5cm are placed in contact find the magnification and power of this combination​

Answer 1

Answer:

-10cm is the correct answer

Explanation:

P

1

=+10D,P

2

=−5D

P=P

1

+P

2

=10−5=5D

f=

5

100

=20cm

Magnification=

u

v

=2

v=2u

v

1

−

u

1

=

f

1

(Lens formula)

⇒

2u

1

−

u

1

=

f

1

⇒

2u

−1

=

f

1

⇒u=

2

−f

=

2

−20

=−10cm

Answer 2

Answer:

Above picture gives you the correct answer

Explanation:

Please mark me as brainliest