Question

An object is placed (90cm) from a convex lens whose focal point is (30)cm. what is the image position (xi)?

choose the answer
- 30m
- 45cm
- 90 cm
- 60 cm

Answer 1

Answer:

Distance of object, u= - 90

Focal length, f= - 30

=> From the mirror formula, we get

\frac{1}{f} = \frac{1}{v} + \frac{1}{u}

f

1

=

v

1

+

u

1

\frac{1}{-30} = \frac{1}{v} - \frac{1}{90}

−30

1

=

v

1

−

90

1

\frac{1}{v} = \frac{1}{-30} + \frac{1}{90}

v

1

=

−30

1

+

90

1

\frac{1}{v} = \frac{-3+1}{90}

v

1

=

90

−3+1

\frac{1}{v} = \frac{-2}{90}

v

1

=

90

−2

\frac{1}{v} = \frac{-1}{45}

v

1

=

45

−1

v = - 45

=> Nature : Real image