## TMA Questions

1. Answer any one of the following questions in about 40-60 words.

(a) In the CGS system force is expressed in dyne, and in SI system is expressed in newtons. Establish the relation between the units of these two systems of force.

(b) Solar constant on earth is 1.36 × 103 W m–2. If Mars is at a distance of 1.52 AU from the sun, calculate the solar constant on Mars applying Stefan’s Law.

2. Answer any one of the following questions in about 40-60 words.

(a) A person is standing on a turn table with some heavy weight in his hands and the table is rotated slowly. When he pulls his hands towards his chest, his angular momentum changes. Explain the change in the value of moment of inertia. How is angular momentum conserved?

(b) The diagonal of a parallelogram are given by the vectors 3𝚤̂+ 𝚥̂+ 2𝑘 and 𝚤̂− 3𝚥̂+ 4𝑘.Find the area of the parallelogram.

3. Answer any one of the following questions in about 40-60 words.

(a) An iron bar 0.50 m long and a copper bar 1.2m long are joined end to end. One end of the iron bar is kept at 80°C while the far end of the copper bar is maintained at 00C by a mixture of ice and water. The outer surface of the bar is logged so that there are no thermal losses. Both bars are of circular cross section diameter 0.16m. At thermal equilibrium the temperature at the junction of the metal Tj. Calculate Tj and rate of energy flow. Thermal conductivity of Iron is 75 Wm-1K -1 and Thermal conductivity of copper is 390 Wm-1K -1

(b) A hawk is hovering above a field at a height of 50 meter. It sees a mouse directly below it, and dives vertically with an acceleration of 9.8 m/s2.
1. At what speed will it be travelling just before it reaches the ground?
2. How long does it take to reach the ground?

4. Answer any one of the following questions in about 100 to 150 words.
(a) A man can jump 1.5 m high on the earth. Calculate the approximate height he might beable to jump on a planet whose density is one quarter that of the earth, and whose radiusis one third of the earth radius.

(b) The engine of an airplane exerts a force of 120KN during takeoff. The mass of the
airplane is 40 tonnes. Calculate
1) The acceleration produced by the engine.
2) The minimum length of the runway needed if the speed required for takeoff is 60 ms-1

5. Answer any one of the following questions in about 100 to 150 words.
(a) Using the equation Speed = frequency × wavelength
1. Calculate the wavelength of the radio signal with these frequencies.
a) 200 kHz
b) 1 MHz
2. Calculate the frequency of radio signal with these wavelength
a) 200 m
b) 10 mm

(b) When the information signal is combined with the carrier wave the amplitude of the
carrier signal is altered. Fig shows the block diagram for a simple amplitude modulated
A) Audio amplifier
B) RF oscillator
C) Modulator
D)RF amplifier

6. Prepare any one project out of the given below:

(a) A Compound microscope is an optical instrument used to view highly magnified imagesof small objects. The magnifying power of a Compound microscope is defined as theratio of the angle subtended by the final image at the eye to the angle subtended by the object at the eye. When both the final image and the object are located at the minimumdistance of distinct vision from the eye written as :

M = 𝜷 𝜶 = 𝒎𝒆 𝒎𝒐 where M is magnifying power, me is the magnification produces by the eye lens and mo is the magnification produced by the objective lens. Consider a compound microscope consisting of an objective lens of focal length 2.0 cm and an eyepiece of focal length 6.25 cm separated by a distance of 15 cm.

1. Identify the distance of the object to the eye piece, so that the final image is formedat the least distance of clear vision.
2. How far should the object be placed from the objective to achieve the positiondescribed in part (i)?
3. Calculate the magnifying power of the microscope, at least in the case of distinct vision?
4. State the intermediate image formed by the objective of a compound microscope.
5. The magnifying power of a compound microscope can be increased with.

(b) Take a spring of length 30 cm. Attach the upper end of this spring to a rigid base and attach a pan to the lower end which has some fixed mass. Now let it hang vertically. Pull and release the spring by 5 cm so that it oscillates up and down relative to its equilibrium position. Now the pan starts oscillating in the vertical direction.

Find the time period of the oscillations and the time of oscillation by using stop watch. Now put a weight of iron on the pan and make it oscillate. Calculate the time of oscillation from the observations. Calculate the weight of that iron using the data obtained from your observations.