Solution By Steps

Step 1: Understanding the Forces in the Sun

The Sun’s internal dynamics involve two primary forces: outward pressure from the hot gas (due to nuclear fusion) and inward gravitational contraction. These forces are crucial in maintaining the Sun’s structure and stability.

Step 2: Analyzing the Outward Pressure

The outward pressure in the Sun is primarily due to the energy released by nuclear fusion in the core. This pressure tends to expand the Sun’s diameter as it pushes against the gravitational pull.

Step 3: Impact on the Magnetic Field

The outward pressure of the hot gas does not directly weaken the magnetic field of the Sun. The Sun’s magnetic field is influenced by its internal convective motions and differential rotation, not by the pressure of the gas.

Step 4: Effect on the Photosphere Temperature

The outward pressure does not cool the photosphere. In fact, the energy from the core, which contributes to the outward pressure, eventually reaches the photosphere and is emitted as visible light and other forms of radiation, maintaining its temperature.

Step 5: Balance with Gravitational Contraction

The most accurate statement among the options is that the outward pressure of hot gas in the Sun is balanced by the inward gravitational contraction. This balance is crucial for the Sun’s stability and prevents it from either collapsing under gravity or expanding uncontrollably.

Final Answer

The correct statement is: The outward pressure of hot gas in the Sun is balanced by the inward gravitational contraction.