Physics Answers

Problem-The intrinsic temperature of a semiconductor is the temperatures at which the intrinsic

carrier concentration equals the impurity concentration. Find the intrinsic temperature for a

silicon sample doped with 1015 phosphorus atoms/cm3

.

How much work is done in lifting a 2-kg ball 0.5m high? Express your answer in a) joules and b) ergs.

Problem - Determine the total number of energy states in silicon between E, and E + kT at T = 300 K.

 Let the angle be the angle that the vector makes with

the measured counterclockwise from that axis. Find

the angle for a vector that has the following components: 

(a)Ax=2.50m, Ay=-0.500m

Electrophoresis is a medical therapy technique used to deliver medicaments into the patients body with help of an electric current. During the procedure, two oppositely charged plates are applied to the body providing flow of the current through the tissue. Suppose that current used in first five procedures was 7 mA (duration of the procedure 6 min) and during the last fifteen procedures 14 mA (duration 15 min). Find charge that passes through the body during 20 electrophoresis procedures.

Electrophoresis is a medical therapy technique used to deliver medicaments into the patients body with help of an electric current. During the procedure, two oppositely charged plates are applied to the body providing flow of the current through the tissue. Suppose that current used in first five procedures was 7 mA (duration of the procedure 6 min) and during the last fifteen procedures 14 mA (duration 15 min). Find charge that passes through the body during 20 electrophoresis procedures.

If the distance of an object is 23 cm in the focal length is -7 what is the distance of the image

A cylinder of mass m and radius R has a moment of inertia of 12mr2. The cylinder is released from rest at a height h on an inclined plane, and rolls down the plane without slipping. What is the velocity of the cylinder when it reaches the bottom of the incline?

A projectile is fired with an initial velocity of 60 m/sec. Upward at an angle of 30° to the horizontal from a point 80m above a level plain. What horizontal distance will it cover before it strikes the plain?

A 9 microcoulomb test charge moves along +x-axis at a speed of 300,000 m/s in the region of 0.75 T magnetic field. Determine the magnetic force on the charge if (a) the field is out of the page; (b) the field is into the page; (c) the field is

downward; (d) the field is upward; (e) the field is 30° above horizontal.