Question

An object is placed upright 25 cm in front of a converging lens with a focal length of 20 cm. A concave mirror with a focal length of 15 cm is placed 120 cm behind the lens. The final image formed is –

• A. Real, enlarged
• B. Virtual , upright
• C. Virtual, inverted
• D. Inverted, diminished

Answer 1

Answer: (A)

Real, enlarged

Answer 2

= $\frac { 1 } { 20 }$

Ž v₁= 100 cm

= $- \frac { 1 } { 15 }$

Ž v₂ = – 60 cm

$\frac { 1 } { v _ { 3 } } - \frac { 1 } { - 60 }$ = $\frac { 1 } { 20 }$

Ž v₃ = 30 cm left of lens

Total magnification = ( – 4) × (– 3) × ( $- \frac { 1 } { 2 }$ ) = – 6 Final image is real, inverted and enlarged.