A)Why is the electrical resistivity of a thin film metal higher than its bulk value? Choose one.

- a) It experiences excessive surface oxidation - b) It has a lower work function - c) Dimensions of the film are comparable to the mean free path

- d) a and b - e) b and c - f) a and b and c

B) Describe how electrical conduction occurs in a lithium polymer electrode?

C) Describe thermal conduction in metals and how it differs from thermal conduction in an insulator. d) What is drift mobility? If we have conduction by ion diffusion in an insulator, is the drift mobility large or small compared to that of a metal? Why?

D) What is drift mobility? If we have electrical conduction by ion diffusion in an insulator or polymeric system, is the drift mobility large or small compared to that of a metal? Why?

Two stones are dropped from the edge of a 60-m cliff, the second stone 2.0 s after the first. How far below the top of the cliff is the second stone when the separation between the two stones is 40 m?

Two ideal linear sheet polarizers are arranged with their transmission axes at 10 degrees and 60 degrees with respect to vertical.

a) If a beam of linearly polarized light with its electric field at 40 degrees with respect to vertical enters the first polarizer, what fraction of its

irradiance will emerge from the second?

b) Replace the polarized beam with a beam of natural, randomly polarized light. Now calculate the fraction of the incident irradiance that emerges

from the second polarizer.

A ceiling fan is turned on and reaches an angular speed of 120 rev/min in 50 sec. It is then turned off and coasts to a stop in 40 s. Find the total number of revolution made before the fan stops

Three point charges are aligned along the x axis.Three point charges lie along the x-axis in the x y coordinate plane. A charge of −4.00 nC is 0.500 m to the left of the origin. A charge of 5.00 nC is at the origin. A charge of 3.00 nC is 0.800 m to the right of the origin.

Find the electric field (in N/C) at the following positions.

(a)    (4.00, 0)

(b)    (0, 4.00)

A 45 kg figure skater is spinning on the toes of her skates at 1.0 rev/s . Her arms are outstretched as far as they will go. In this orientation, the skater can be modeled as a cylindrical torso (40 kg , 20 cm average diameter, 160 cm tall) plus two rod-like arms (2.5 kg each, 69 cm long) attached to the outside of the torso. The skater then raises her arms straight above her head, where she appears to be a 45 kg, 20-cm-diameter, 200-cm-tall cylinder.

What is her new rotation frequency, in revolutions per second?

Q.2.Two sinusoidal waves combining in a medium are described by the wave functions y1 = (0.3m ) cos (2πx +40πt) y2=( 0.3 m) sin (2πx +40πt ) (i). What will be the resultant displacement wave function expression and what type of the resultant wave will be generated by it. [3] (ii). What will be the amplitude, frequency and the speed of the resultant wave? [3] (iii).Find the transverse velocity and transverse acceleration at x= 0.25m, and t= 2sec?

a) A block ice of mass 1kg has a temperature of -5°C and gets placed in Calorimeter A, filled with 10l of water at a temperature of 15°C. Determine the temperature Teq at equilibrium.

b) An identical block of ice gets placed in calorimeter B, filled with 2l of water at a temperature of 15°C. Determine the amount of ice, Mice, left at equilibrium.

Cwater = 4190J/kg*K, Cice = 2100J/kg*K, Lf= 3.34*10^5 J/kg

Describe the principle behind the working of a motor and the generator?Then, explain the “motor- generator duality”

How do magnetic field lines from the coil compare with those of permanent magnet? Explain why they have similar shape. What are the sources of these magnetic fields?

Solve using any method you would like, but show your work. Suppose we were considering the Atwood’s machine pictured at right. A block of mass M1 = 1.5 kg is on a surface with coefficient of friction µ = 0.10, which is tilted at an angle α = 30º. A second block of mass M2 = 3.5 kg is hanging vertically. The two blocks are connected via an ideal massless string that passes over a pulley of mass mp = 0.55 kg and radius rp= 7.5 cm which can be treated as a solid disk. At time t0 block 2 is released from rest and it begins to fall.

a. Determine the magnitude of the friction force. Show your work

b. Determine the speed of the blocks when block 2 hits the floor, 0.35 m below where it starts. Show your work

c. After block 2 hits the floor, how much farther will block 1 slide up the incline before coming to rest? Show your work (hint, once block 2 hits the floor the tension in the string goes to zero – will it have any effect anymore?)

Write and explain the integral form of Maxwell’s Equations as applied to free space, that is, in the absence of any dielectric or magnetic material.

At the equator, near the surface of the Earth, the magnetic field is approximately 50 ?? northward, and the electric field is about 100 N/C downward in fair weather. Find the magnitude and direction of gravitational, electric, and magnetic forces on an proton in this environment, assuming the proton has an instantaneous velocity of 5?106m/s directed to the west.