Question

an object 4 cm from concave mirror and images formed at a distance of 18 cm from the mirror find two possible value of focal length mirror what are the corresponding size and nature of the image
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Answer 1

A 4.00-cm tall light bulb is placed a distance of 45.7 cm from a concave mirror ... The negative values for image height indicate that the image is an inverted image. ... case in physics, a negative or positive sign in front of the numerical value for a ... the object is located beyond the center of curvature (which would be two focal ...

Answer 2

Answer:

u =-4cm and for v (image distance) it is both -18cm and +18 cm,,,,,, -18 cm for for real and inverted image and +18cm for erect and virtual image then 1/f=1/v+1/u using mirror formula

first v=-18 cm and u =-4 cm ,,1/f= -1/18-1/4 ,, 1/f=(-4-18)/72 then 1/f = -22/72 means f is - 72/22 then putting the value V is +18 then 1/f= 1/18-1/4 then 1/f=4-18/72 means f is -72/14 cm