Question

A laser beam is used for carrying out surgery because it
A.) Is highly coherent
B.) Is highly directional
C.) Can be sharply focused
D.) Is highly monochromatic

Answer 1

Hint: Surgery is a life and death issue. Lasers used in surgery need to be extremely precise on the tissue at action. It cuts through tissues which need to be surgically removed. For such a purpose lasers should be extremely focused.

Complete step by step answer:
A laser is a device that emits light through a process of optical amplification based on a type of emission and stimulated emission. The term laser is a short form for light amplification by stimulated emission of radiation. In a surgery, the effect of the beam is restricted to the affected area so a laser beam should be sharply focused.
Hence the correct answer is option C.

Additional information:
There is a wide range use of a laser in the day to day life. Lasers are used in cutting and welding materials, laser printers, DNA sequencing instruments, fiber-optic, optical disk drives, semiconductor chip manufacturing (photolithography), and free-space optical communication, barcode scanners, laser surgery and skin treatments, military and law enforcement devices for marking targets and measuring range and speed. A blue laser and phosphor is used in inexpensive cars to give a highly defining bright white light. Consumption of electricity is really high for a laser to operate.

Note:
Due to the coherence property of lasers they differ from any other light source. Lasers are spatially coherent which means they pass through narrow slits and diffract less. Laser beams can be focused to very tiny areas leading to high irradiance. The power loss of a laser is very less so it can be concentrated at a very large distance.