Question Library

In the day time, it is possible to see under shady areas such as under a tree because light has undergone

The distance between a concave mirror and an object placed in front of it is 1.0m. If the raduis of curvature of the mirror is 4.0m, the image formed will be

The image of an object formed by a convex mirror is

When viewed straight down, a fish in a pond is

A converging lens and a screen are placed 20 cm and 80 cm respectively from an object in a straight line so that a sharp image of the object is formed on the screen. If the object is 3cm high. Calculate the height of the image formed

a sound wave is produced fron a source ans an echo is heard t seconds afterwards. If d is the distance of the reflecting surface from the source, v the speed, p the wavelength and T the period of the wave, then

Both \(\gamma\)-rays and X-rays i. can be produced by thermionic emission ii. have low frequencies iii. have short wavelengths. Which of the statements above is/are correct?

Explain plane polarized light

(a) The equation y = \(\alpha\) sin (wt - kx) represents a plane wave travelling in a medium along the x-direction, being the displacement at the point x at time t. (i) Given that x is in metres and t is in seconds, state the units of k and w (ii) What physical quantity does \(\frac{W}{k}\) represent? Justify your answer (iii) State whether the wave is travelling in the positive or negative x-direction. (b)(i) What are beats? (ii) A sonometer wire has a frequency of 259 Hz. It is sounded alongside a tuning fork of frequency 256 Hz. Calculate the beat frequency (iii) The sonometer wire in (b)(ii) above is under a tension of 1200 N. If a metre of the wire has a mass of 0.03 kg, calculate the length l of the wire when it is vibrating in the fundamental mode. (c) List two similarities between the human eye and the photographic camera.

Using the above diagram as a guide, carry out the following instructions. Fix a metre rule on the bench with its graduated side facing up. Place the illuminated object at the 0cm end and the screen at the 100cm end of the rule such that the distance d between the illuminated object and screen is 100cm. Record the distance d. Also, evaluate and record d\(^{2}\). Place and move the Converging lens between the illuminated object and the Screen until a sharp diminished image of the object is formed on the screen. Read and record the position Ih of the lens. Now move the lens towards the object until another sharp image of the object is formed on the Screen. Read and record the new position \(l_2\) of the lens. Evaluate and record L= (\(l_1\) - \(I_2\)), also evaluate L\(^{2}\) and D = d\(^{2}\) - L\(^{2}\). Repeat the procedure for four values of d= 85, 75, 65 and 55cm. Tabulate your readings. Plot a graph or Don the vertical axis against d on the horizontal axis. Determine the slope, s, of the graph. Evaluate k = \(\frac{s}{4}\). State two precautions taken to obtain accurate results. (b)i. Explain the statement the focal length of a converging lens is 15cm. ii. Distinguish between a real image and a virtual image.

I. They should be identical II. They should originate from the same source. III. They should be coherent. IV. They should be monochromatic. from the statements above, the conditions for two waves to interfere are?

In a large telecommunications auditorium, perforated absorbent materials are used to line the ceiling so as to

The phenomenon of light bending round an obstacle is?

The instrument used by designers to obtain different color pattern is called?

A glass plate 0.9cm thick has a refractive index of 1.50. How long does it take for a pulse of light to pass through the plate? [c = 3.0 x 10\(^8\) ms-1]