Physics 2022 Jamb Examination

Saturated vapour pressure (SVP) of a liquid increases as temperature increases because higher temperatures provide molecules with more kinetic energy to escape the liquid phase into the vapour phase. However, this relationship is not a straight line; it follows an exponential curve described by the Clausius-Clapeyron relation. Therefore, the increase is non-linear.

The work done in stretching an elastic string or spring is stored as elastic potential energy. According to Hooke's Law, the force \( F = kX \). The energy is the area under the force-extension graph, which is a triangle:\[ \text{Energy} = \frac{1}{2} \times \text{Force} \times \text{Extension} \] \[ \text{Energy} = \frac{1}{2} \times (kX) \times X = \frac{1}{2}kX^2 \]

The pressure \( P \) in a fluid at a certain depth \( h \) is given by the formula:\[ P = h\rho g \]Given:
\( P = 9100 \; \text{Nm}^{-2} \)
\( \rho = 2000 \; \text{kgm}^{-3} \)
\( g = 10 \; \text{ms}^{-2} \)
We need to find \( h \):\[ 9100 = h \times 2000 \times 10 \] \[ 9100 = 20000h \] \[ h = \frac{9100}{20000} \] \[ h = 0.455 \; \text{m} \]

A good thermometric liquid should expand uniformly with temperature. Water is unsuitable because of its anomalous expansion: it contracts when heated from 0 ºC to 4 ºC, and expands thereafter. This means a single volume could represent two different temperatures. Additionally, water wets glass (clings to the sides), has a high heat capacity (takes a long time to reach equilibrium), and is transparent (hard to read).

In a second-class lever, the Load is located between the Fulcrum and the Effort (F-L-E). A wheelbarrow is the classic example: the wheel is the fulcrum, the contents are the load in the middle, and the handles are where the effort is applied.

Sugar tongs are third-class (Effort in middle), while claw hammers and pliers are first-class (Fulcrum in middle).

During the day, the land heats up faster than the sea. The air above the land becomes hot, less dense, and rises. This creates a low-pressure area over the land. The cooler, denser air over the sea then moves in to replace the rising air, resulting in a breeze blowing from the sea to the land.

The ferrule is a high-precision cylinder, usually made of ceramic, plastic, or metal, that holds the bare glass fibre. It has a tiny hole in the centre where the fibre enters and is fixed in place, ensuring the fibre is accurately aligned for connection within the housing.

A helioscope is a specific type of telescope or an attachment for a telescope designed for observing the sun without damaging the observer's eyes. It often uses a 'Herschel wedge' or solar filters to reduce the intense light and heat.
A standard telescope is dangerous for direct solar viewing, a stroboscope is for measuring cyclic motion, and a sun meter is not a standard astronomical instrument.

A lunar eclipse (eclipse of the moon) happens when the Earth passes directly between the Sun and the Moon. In this position, the Earth casts its shadow (the umbra and penumbra) onto the Moon, blocking the sunlight that normally reflects off it.

Weight (\( W \)) is calculated by the formula \( W = mg \). Since the mass \( m \) of the body remains constant, weight is directly proportional to the gravitational acceleration \( g \).
If:\[ g_{\text{moon}} = \frac{1}{6} g_{\text{earth}} \] Then:\[ W_{\text{moon}} = \frac{1}{6} W_{\text{earth}} \] \[ 6.0 = \frac{1}{6} W_{\text{earth}} \] \[ W_{\text{earth}} = 6.0 \times 6 = 36.0 \; \text{N} \]