wld_lshy - Engineering - physics

MINISTRY OF MANPOWER NIZWA COLLEGE OF TECHNOLOGY

Engineering Department

FINAL ASSIGNMENT: Semester-2, 2019-20 Course Code: PHYS1211: Course Name: Physics 2

Date & Time of Upload

13-05-2020 9:00 AM

Submission Deadline & Date

15-05-2020 08:00 AM

Instructions to the Students

1. The Final Assignment will be available in Moodle at 9:00 am on the date of examination.

2. This is an open resource examination; there are (5) pages. Students are allowed to refer to any digital

materials (Internet, Proquest, Masader, and OER) with proper referencing and citation for any research

question.

3. A student has to answer the questions typewritten in the Word (.docx) format. Figures / Diagrams,

equations and solving of problems can be written by hand and added to the document as a picture/image.

4. Save the assignment file using the student ID, Course code, & Section number [E.g.: 22s1234 – PHYS1211,

Section (x)].

5. A student should submit the answers through the Turnitin link provided in moodle page. If any problem

occurs, send it to the course tutor email [Email address, [email protected],

[email protected], [email protected] ]

6. Students are encouraged to upload the answers in the moodle at least two hours before the deadline to

avoid any technical issues.

7. In case of any technical problem in opening or submitting your assignment, please contact your course

tutor through email and copy to the Department Head.

8. Any form of cheating is punishable. Students involved in cheating will be treated according to the

Plagiarism and Academic Integrity Policies.

9. Students are advised to write the answers in their own words. Based on the plagiarism policy and the

department approved similarity level, the marks will be deducted for the plagiarized [Copied] answers.

10. Students should complete their assignment within the given time. Assignments submitted after the

deadline will be marked 0.

Final Assignment

Page 2 of 5

QUESTIONS [ ANSWER ALL THE QUESTIONS]

EACH QUESTION CARRIES 5 MARKS

1 The L-shaped wire is shown in Fig. lies in the XY plane. In the

presence of a uniform magnetic field B=15000G, the wire carries a

current of 2.5A from “point a to point c”.

(a) Find the net force exerted on the wire. Write a full equation

with angle values. (3 marks)

(b) Show that this net force is the same as if the wire were a

straight segment from point “a to point c”. (2 marks)

2 A sinusoidal electromagnetic wave of frequency 40 MHz travels in free space in the x-direction.

(a) What is an electromagnetic wave and how it can be produced? (1 mark)

(b) Determine the wavelength and time period of the wave. (2 marks)

(c) At some instant, the electric field has its maximum value of 750 N/C and is along y-axis. Calculate the

magnitude and direction of the magnetic field at this position and time. (2 marks)

3 (a) A wave is modeled by the wave function. (3 marks)

𝑦(𝑥, 𝑡) = 0.55 m sin [ 2𝜋

4.5 𝑚 (𝑥 − 18.00

𝑚

𝑠 𝑡)]

What are the amplitude, wave number, wavelength, wave speed, frequency, and period of the wave?

(b) Three waves that were sent down a string

at different times, shown in the Fig. The

tension in the string remains constant.

(2 marks)

(i) Rank the waves from the lowest frequency

to the highest frequency.

(ii) Rank the waves from the lowest amplitude

to the highest amplitude.

4 The figure shows a person is warming his hands over the

fire.

(a) Explain how the heat transfers from fire to hands.

What is the name of this method? (2 marks)

(b) A wood stove is used to heat a single room. The stove

is cylindrical in shape, with a diameter of 40 cm and a

length of 50 cm, and operates at a temperature of 400°F.

If the temperature of the room is 70°F, determine the

amount of radiant energy delivered to the room by the

Final Assignment

Page 3 of 5

stove each second if the emissivity is 0.920. (3 marks)

5 The figure shows a ray of light, from the top of an object PQ,

passing through two glass prisms.

(a) Complete the path through the two prisms of the ray

shown leaving Q. (1 mark)

(b) The light of wavelength 600 nm travels from P to A. If

object PQ is in air, then calculate the wavelength and speed

of light in the prism of index 1.5. (3 marks)

(c) Explain why the ray AB reflects through 90° at B and does

not pass out of the prism at B. (1 mark)

6 A cable with a linear density of 200 g/m is hung from telephone poles. The tension in the cable is 500 N. The

distance between poles is 11.25 meters. The wind blows across the line, causing the cable to resonate. A

standing waves pattern is produced that has a wavelength of 4.5 m between the two poles.

(a) What is the speed of the wave? And what is the frequency of this harmonic? (3 marks)

(b) Draw this standing wave pattern and identify the exact position of nodes and antinodes on the cable.

(2 marks)

7 (a) The structure of optical fiber cable is shown in Fig (a).

Calculate the critical angle for the core-cladding boundary.

If the speed of light in core and cladding is 1.96x10 8 m/s

and 2.03x10 8 m/s respectively. (2 marks)

(b) Explain the structural properties of Core and Cladding.

(2 marks)

(c) The diagram (b) shows a ray of light inside the core of a

fibre. The ray is incident on the core-cladding boundary at an

angle of 80⁰. State what happens to this ray of light when it is

incident on the core-cladding boundary as shown?

(1 mark)

Final Assignment

Page 4 of 5

8 The figure is a setup that can be used to measure

magnetic fields. A rectangular coil of wire contains N

turns has a width w. The coil is attached to one arm of

a balance and is suspended between the poles of a

magnet. The field is uniform and perpendicular to the

plane of the coil. The system is first balanced when the

current in the coil is zero. When the switch is closed,

and the coil carries a current I, a mass m must be

added to the right side to balance the system.

(a) Find an expression for the magnitude of the

magnetic field and determine its direction. (2 marks)

(b) Why is the result independent of the vertical

dimension of the coil? (1 mark)

(c) Suppose the coil has 50 turns and width of 5.0 cm.

When the switch is closed, the coil carries a current of

0.30 A, and a mass of 20.0 g must be added to the

right side to balance the system. What is the

magnitude of the magnetic field? (2 marks)

9 (a) A steel bullet of specific heat 460 J/kg°C is launched at a speed of

200 m/s. It embedded in a rod of wood. If 65% of bullet’s kinetic energy is

lost and used to heat and raise its temperature. How much the

temperature increases in the bullet? (2 marks)

(b) All Omani people use thermos flask to keep a coffee hot.

Explain how the flask is designed to slow down all forms of heat transfer?

(2 marks)

(c) Why the days are very hot and nights are cold in the desert? Explain.

(1 marks)

10 (a) An object is placed 20 cm away from a lens that has an index of refraction 1.5. The magnification of the

object produced by the lens is –1/4.

(i) Determine the type of lens and describe the image. (1 mark)

(ii) What is the focal length of the lens? (2 marks)

(b) The figure shows a thin converging lens. The two focal points are shown.

A vertical object, 2 cm height, is to be positioned to the left of the lens, with one end on the principal axis.

On the Fig., Draw the object in a position which will produce a virtual image, labelling the object with the

letter O. (1 mark)

(c) Draw rays to show how the real image is formed. (1 mark)

Final Assignment

Page 5 of 5