Question

Where should an object be placed in front a convex lens to get a real image of the size of the object?
1. At the principal focus of the lens
2. At twice the focal length
3. At infinity
4. Between the optical centre and principal focus of the lens

Answer 1

Answer:

4. Between the optical centre and principal focus of the lens

Answer 2

1: at infinity

2:at 2f1

3: at focus

4:Any where between infinity and optical centere