56. An object is 80cm in front of a lens. An image forms 10 cmbehind the lens. T

Question

56. An object is 80cm in front of a lens. An image forms 10 cmbehind the lens. The lateral magnification:    a. is 8    b. is .125    c. is -.125    d. cannot be found with the informationgiven 57. It is desired to protect an image of an object 4 timesactual size with a lens of focal length of 20cm. What objectdistance should be used?    a. 5 cm    b. 25 cm    c. 80 cm    d. 100 cm     56. An object is 80cm in front of a lens. An image forms 10 cmbehind the lens. The lateral magnification:    a. is 8    b. is .125    c. is -.125    d. cannot be found with the informationgiven 57. It is desired to protect an image of an object 4 timesactual size with a lens of focal length of 20cm. What objectdistance should be used?    a. 5 cm    b. 25 cm    c. 80 cm    d. 100 cm    

Explanation / Answer

56. An object is 80cm in front of a lens. An image forms 10 cmbehind the lens. The lateral magnification:    a. is 8    b. is .125    c. is -.125    d. cannot be found with the informationgiven
m=v/u=10/80=0.125
so option B is correct.
57. It is desired to protect an image of an object 4 timesactual size with a lens of focal length of 20cm. What objectdistance should be used?    a. 5 cm    b. 25 cm    c. 80 cm    d. 100 cm
m=4=v/u
so v=4u
1/u+1/v=1/f
1/u+1/4u=1/20=>u=25cm
so option B is correct.
  

Related Questions

Navigate

• Browse (All)
• Browse 5
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.