I assume you are comparing it with a mirror. The wall has surface irregularities that are much larger than the wavelength of the light, so the light gets reflected in many different directions, not just in a single direction.
No you dont need a screen, you could just use a wall
no it does not produce real image . it produce virtual and erect image
Plane mirrors produce a virtual image.
No, convex lens does not produce a real image. It reflects the real image
I see an Image on the wall.
An image does not produce an image. However, a concave mirror, specifically one witha parabolic figure, forms an image in its focal plane of an infinitely distant object.
No, ultrasound is a technique used to produce an image of the fetus.
Definitely Virtual Image
A real image as well as a virtual image.
The light reflecting off of it in your line of site
real and upright image
No, only the virtual image will be obtained.