Entrance Guru: Physics Model questions and answers part 2

1) It is desired to photograph the image of  an object placed at a distance of 3 m from plane mirror.The camera .which is at a distance of 4.5 m from mirror should be focussed for
a distance of :

 a) 3 m   

 b) 4.5 m

 c) 6 m

 d) 7.5 m

2) A convex mirror has a focal length f . A real object ,placed at a distance f  in front of it from the pole,produces an image at :

 a) 2f

 b) f/2

 c) f

 d) ∞

3)  If an object is 30 cm away from a concave mirror of focal length 15 cm ,the image will be:

 a) erect

 b) virtual 

 c) diminished 

 d) of the same size

4) The figure width for red color as compered to that for violet color is approximately :

 a) 3 times

 b) double

 c) 4 times 

 d) 8 times

5) Thomson discovered 

 a) x-rays

 b) Isotopes

 c) Canal rays 

 d) Fusion

Answers

1) d) 7.5 m

2) b) f/2

3) d) of same size

4) b) double

5) c) Canal rays