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If the period of the pendulum in the preceding sample problem were 24s how tall would the tower be
Experiment 1
Materials: salt, fine pepper, small dish, plastic comb, wool/cotton cloth.
Procedure:
1. Put the salt and fine pepper separately in a small dish
2. Rub the plastic comb with cloth repeatedly.
3. Hover the comb over the salt and fine pepper.
Questions:
1. What do you think is the charge of the salt and fine pepper in step 1?
2. What do you think is the charge of the comb in step 2?
3. explain what happened in the experiment.
Indicate on an energy level diagram the conduction and valence bands, donor and acceptor states and the position of Fermi level for
(i) an intrinsic semiconductor.
(ii) a n-type semiconductor.
(iii) a p-type semiconductor.
Question 4
4.1. The conductivity of silver is 6.5 x 107per Ohm per m and number of conduction electrons per m3 is 6 x 1028. Find the mobility of conduction electrons and the drift velocity in an electric field of 1 V/m. Given m = 9.1 x 10–31 kg and e = 1.602 x 10–19 C.
4.2 What is Lorentz number? The thermal and electrical conductivities of Cu at 200C are 390 Wm-1K-1 and 5.87 x107W-1m-1 respectively. Calculate Lorentz number.
5.1 The electron and hole mobilities in a Si sample are 0.135 and 0.48m2/V-s respectively. Determine the conductivities of intrinsic Si at 300 K if the intrinsic carrier concentration is 1.5 x 106 atom/m3. The sample is then doped with 1023 phosphorus atom/m3. Determine the equilibrium holeconcentration, conductivity, and position of the Fermi level relative to the intrinsic level.
The relative permittivity of a die electric is 2.25.(a) What is its permittivity (b) What will be the capacitance of this electric is inserted into a 7.8 air capacitor?
Differentiate the following different types of materials. Give examples.
diamagnetic
paramagnetic
ferromagnetic
antiferromagnetic
ferrimagnetic
superparamagnetic
If the speed of the bob at the lowest point A is 0.84 m/s, what is its KE at this point?
1.A beam of light enters water at an angle of 60 degrees relative to the normal of the water surface . Find the angle of refraction?
2.Light passes from air into water . If the angle of refraction is 20° ,what is the index of refraction of the plastic?
A small particle has charge -5.00 uC and mass
2.00 x 10-4 kg. It moves from point A, where the electric poten-
tial is VA = +200 V, to point B, where the electric potential is
VB = +800 V. The electric force is the only force acting on the
particle. The particle has speed 5.00 m/s at point A. What is its
speed at point B? Is it moving faster or slower at B than at A?
A point charge q1, is held stationary at the origin. A second charge q2 is placed at a point a, and the electric potential energy of the pair of charges is −6.4×10 −8J. When the second charge is moved to point b, the electric force on the charge does 4.2×10 −8 J of work. What is the electric potential energy of the pair of charges when the second charge is at point b?
