Question

concave mirror provides an image at a distance of 75 cm from the mirror when the object is kept at a distance of 40 cm from the mirror image being real where will the image be formed if object is at a distance of 60 cm from the mirror
​

Answer 1

Answer:

Explanation:

Answer

u=−60cm

u

−v

​

=  

2

1

​

⇒  

−60

−v

​

=  

2

1

​

 

⇒v=30cm

⇒  

v

1

​

+  

u

1

​

=  

f

1

​

 

⇒  

f

1

​

=  

30

1

​

+  

−60

1

​

 

⇒  

f

1

​

=  

60

2−1

​

=  

60

1

​

 

⇒f=60cm

Now magnification=  

3

1

​

 

u

−v

​

=  

3

1

​

⇒v=  

3

−u

​

 

∴  

v

1

​

+  

u

1

​

=  

f

1

​

⇒  

3

−u

​

 

1

​

+  

u

1

​

=  

f

1

​

 

⇒  

u

−3

​

+  

u

1

​

=  

60

1

​

⇒  

u

−2

​

=  

60

1

​

 

⇒u=−120cm

∴ Object should be placed at 120cm.