The distance between the lenses in a compound microscope is 18 cm. the focal length of the objective is 1.5 cm. if the microscope is to provide an angular magnification of -67 when used by a person with a normal near point (25 cm from the eye), what must be the focal length of the eyepiece?

The correct answer is 3.58 cm.

Explanation:

For a compound microscope where the object is placed very close to the focal point of the objective, it is found that the angular momentum is given by:  

m = - ( L - fe) N / fo *fe

m = - (18 - fe) (25) / 1.5 * fe

It is given that m = -67

so, 67 = (18-fe) (25) / 1.5 * fe

100.5 fe = 450 - 25 fe

125.5 fe = 450

fe = 450 / 125.5

fe = 3.58 cm

answer; (b) clear with a slight blue tint;

the ems is the abbreviation for the emergency medical services. it is a service provided by a group of medical professionals specialised doctors and other healthcare staff.

any one can call 911 in case of any medical emergency and a group of health care professional will come and give the treatment required. every day the ems staff receive many phone call, which are related to different types of medical emergencies, out of which 25-28% are exclusively related to the respiratory issues.

so, the correct answer is 25-28%.