Light of wavelength 500 nm is incident on a thin sheet of plastic ...

[Caiter2013]

Light of wavelength 500 nm is incident on a thin sheet of plastic film (n= 1.50 ) in air. What is the thinnest the sheet can be so that the reflected light from the surfaces undergoes constructive interference?
 
  A)
 
  50 nm
  B)
 
  250 nm
  C)
 
  333 nm
  D)
 
  167 nm
  E)
 
  83 nm

Question 2

A man is holding an 8.00-kg vacuum cleaner at arm's length, a distance of 0.550 m from his shoulder. What is the torque on the shoulder joint if the arm is horizontal?
 
  A)
 
  0.242 Nm
 
  B)
 
  4.40 Nm
 
  C)
 
  43.2 Nm
 
  D)
 
  14.5 Nm
 
  E)
 
  0 Nm

[Koolkid240]

Answer to Question 1

E

Answer to Question 2

C

[Caiter2013]

TYSM

[mochi09]

Excellent