A convex lens makes a real image of 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object or the screen, we get a real image on the screen, which is 16 cm long. The length of the object is :

Question

A convex lens makes a real image of 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object or the screen, we get a real image on the screen, which is 16 cm long. The length of the object is : (A) 1/4 cm (B) 8 cm (C) 20 cm (D) 2 cm

Tardigrade Admin · Accepted Answer

From displacement method, the length of object is given by O=√I1I2=√4× 16=√64=8cm

Q. A convex lens makes a real image of 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object or the screen, we get a real image on the screen, which is 16 cm long. The length of the object is :

1/4 cm

8 cm

20 cm

2 cm

From displacement method, the length of object is given by $O = I_{1} I_{2} = 4 \times 16 = 64 = 8 c m$

Q. A convex lens makes a real image of 4 cm long on a screen. When the lens is shifted to a new position without disturbing the object or the screen, we get a real image on the screen, which is 16 cm long. The length of the object is :

1/4 cm

8 cm

20 cm

2 cm

From displacement method, the length of object is given by O=I1​I2​​=4×16​=64​=8cm

From displacement method, the length of object is given by $O = I_{1} I_{2} = 4 \times 16 = 64 = 8 c m$