Correct Answer: Option 1 – Violet

The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 750 nm. Following diagram shows the different wavelengths and their frequency visible spectrum

From the visible spectrum violet has the lowest wavelength; that is 380-450 nm.

Based on these arguments, the rest of the options are incorrect

Correct Answer: Option (3) – 5000^o C

The earth is divided into four main layers namely inner core, outer core, mantle, and crust. The outer skin of the earth is known as earth is known as the crust. It is 30-40 km thick below the continents and even thicker beneath mountain regions. But only about 10 km below the oceans.

Below the crust is the mantle, a denser, solid zone in which earthquake waves travel with. Mantle itself is divided an inner mantle and upper mantle.

Inner Mantle: the inner mantle can be found between 190 miles (300 km) and 1,800 miles (2,890 km) below the earth’s surface. The average temperature is 5400 ºF (3000ºC)

The outer mantle is a lot thinner than the inner mantle. It can be found between 7 miles (10 km) and 190 miles (300 km) below the surface of the earth. You can divide the outer mantle into two different layers. The bottom layer is tough liquid rock and probably consists of silicates of iron and magnesium. The temperature in this part is between 2520 ºF (1400ºC) and 5400 º F (3000ºC)

The base of the mantle is at about 2900 km, below which is core. The outer core extending from 2900 km to 5150 km is liquid. The inner core, from 5150 km to the centre of the earth at 6371 km, is solid. The temperature in the outer core is about 7200 - 9032 ºF (4000-5000ºC). The temperature in the inner core is about 9032 - 10832 ºF (5000-6000 ºC).

The core-mantle boundary (or CMB in the parlance of solid earth geophysicists) lies between the Earth's silicate mantle and its liquid iron-nickel outer core. This boundary is located at approximately 2900 km of depth beneath the Earth's surface. The temperature of the core-mantle boundary is between 4000-5000ºC

Correct Answer: Option (4)

Solar radiation pass through the atmosphere and part of the solar radiation is absorbed by the earth surface. Then solar radiation (Short waves) is converted to heat energy causing the emission of long wave radiation (Infrared waves - IR). This IR radiation release to the atmosphere and part of that radiation is absorbed by CO₂ molecules emits back. This process causes to increase the temperature of the earth’s atmosphere and is called as ‘green house effect’. This is mainly governed by CO₂ concentration of the atmosphere