2003 - JAMB Physics Past Questions and Answers - page 2

R.H = Partial Pressure of Water Vapour Presentx100_1S.V.P at temperature of atmosphere
= _10x100_117.50
= 57.14%

Here's how to solve the problem: 1. **Understand Resonance in a Closed Tube:** Resonance in a closed tube (closed at one end, which is the case as water is poured in) occurs when the length of the air column is a quarter of the wavelength (fundamental frequency) or an odd multiple of a quarter wavelength. The formula for the fundamental frequency is: *L* = λ/4. Higher resonance points occur at 3λ/4, 5λ/4, etc. We're looking for the maximum height, meaning the air column will be at its first resonance. 2. **Calculate the Wavelength (λ):** Use the formula: *v* = *f*λ, where: * *v* = speed of sound (340

Form the lens formula = ¹/_U + ¹/_V = ¹/_f
=> ¹/₁₀ + ¹/₂₅ = ¹/_f;
∴ (5 + 2) / 50 = ¹/_f
∴ f = ⁵⁰/₇cm
since the image is observed on a screen, it is a real image. Thus magnification
M = ^f/_U-f

=	__50/7
10 - 50/7

∴ M =	50/7
20/7

= ⁵⁰/₇ x ⁷/₂₀ = 2.5

Two thermal objects are said to be in a thermal equilibrium when the temperature of both objects are equal. Generally, heat flows from an object at a higher temperature to the one at a lower temperature until both temperature are the same, during which the two bodies are said to be in thermal equilibrium

In vibration in a closed pipe/tube as shown in the figure, fundamental note is produced at the first position of resonance. When the length of the air column L = ^λ/₄; => λ = 4L. Since the open end of the tube is taken as an antinode; and closed end as the node.
Thus the associated frequency is given by
f = ^V/_λ = ^V/_4L
∴ f = ^V/_4L

The increase in length of the steel rail is given by
= α 10
= 11 x 10^-6 x 20 x (40 -20)
= 11 x 10^-6 x 20 x 20
= 4.4 x 10^-3
∴ Final length will be original length plus increase in length
= 20 + 4.4 x 10^-3
= 20 + 0.0044
= 20.0044m

The number of images to be observed will be infinite

For a concave mirror to produce an image at infinity, the image has to be place at the principal focus of the mirror

In general intensity of a wave is the rate of flow of energy across unit area normal to the direction of propagation of the wave intensity α¹/_r² where r is the distance away from the point source. Thus if the distance from the point source of the sound wave is doubled, then the intensity will be decreased by a factor of 4