RRB JE Electrical Solved Question paper 2013 | RRB JE Electrical

Answer.2. 4°C

Explanation:-

Density of Water is Maximum at 4°C

As water is heated from 0°C (melting point of ice) onwards, more and more hydrogen bonds are broken and the molecules come closer and closer in the liquid state. As a result, the volume decreases, and hence density increases. This process continues up to 4°C where water attains the maximum density. On heating further, the kinetic energy of the molecules increases, and the molecules move apart causing expansion. Hence up to 4°C, the contraction effect predominates and above 4°C, the expansion dominates over contraction, and overall density decreases. So the value of density is maximum at 4°C.

Answer.4. Pale blue syrupy Liquid

Explanation:-

Pure hydrogen peroxide (H₂O₂) is a pale blue syrupy liquid as it is more associated through hydrogen bonding than H₂O. Pure hydrogen peroxide is weakly acidic, while in dilute aqueous solution it is more acidic than water.

Answer.1. Electrolysis

Explanation:-

Electrolysis is a process of detaching or dissociating bonded elements and compounds by passing through them an electric current. Water electrolysis decomposes H₂O into hydrogen and oxygen gas. Care must be taken in choosing the correct electrolytes, nominally substances that contain free ions and hence behave as an electrically conductive medium. Electrolytes dissolve and dissociate into cations Positive ions, +) and anions Negative ions, -) that carry the current. As we have seen in Chapter 2, such processes can occur in an electrolysis cell, or electrolyzer, which consists of two electrodes, cathode, an anode, where reduction and oxidation reactions simultaneously take place forming H₂ (at the cathode) and O₂ (at the anodes).

$2H_2{O}_{\left(l\right)}\to 2H_{2\left(g\right)}+O_{2\left(g\right)}$ – water decomposes into hydrogen and oxygen in the presence of an electric current;

Answer.1. Solubility Limit

Explanation:-

Solubility limit: Maximum concentration of solute atoms that may dissolve in the solvent to form a solid solution. For example, sugar and water. The solubility limit of sugar in water depends upon the temperature of water.

Answer.3. 46.6

Explanation:-

Urea has the highest nitrogen content (46.6 percent) of the solid nitrogen fertilizer.

Answer.4. Low specific heat and high conductivity

Explanation:-

The cooking pot should have low specific heat and high conductivity. If the material has a high thermal conductivity i.e. more heat will form when the Pot is on fire. The quantity of heat required to heat up the material is also important, this is the specific heat & thermal capacity, and in this case, if the pot has a low specific heat then it will get hot more quickly for a given heating condition (i.e. fire) than one with high specific heat.

Answer.1. Increases

Explanation:-

A liquid behaves as if there is a force pulling its surface together. It takes energy to increase the surface area of a liquid by, for instance, making many smaller drops from one large drop. The amount of energy needed to increase the surface area of a liquid is called the surface tension of the liquid. Surface tension is measured in Si units of newtons per meter. Liquids with large intermolecular forces have large surface tensions.

Answer.2. Red, blue, Green

Explanation:-

Visible light, consisting of radiation with wavelengths from 400 to 700 nm, represents a very small portion of the electromagnetic spectrum. Within this region are all the colors you see when white light passes through a prism: red, orange, yellow, green, blue, indigo, and violet (ROY G BIV). Each color is identified with a portion of the wavelength range.

Isaac Newton did experiments with light and established that the mind’s perception of color requires only three colors. When we see the white light, we are seeing a mixture of all of the colors—in other words, the superposition of red, green, and blue. 

The color wheel shows the three primary colors i.e red, green, and blue as overlapping disks arranged in a triangle. The secondary colors—cyan, magenta, and yellow—appear where two disks overlap. The overlap of all three disks in the center produces white light. The colors we perceive are determined as follows:

• Light of a single primary color is perceived as that color: Red light is perceived as red, green light as green, blue light as blue.
• The light made up of two primary colors is perceived as the color shown where the disks in overlap: Red and green light together appear yellow, green and blue light together are perceived as cyan; and red and blue light are perceived as magenta.
• The light made up of the three primary colors is white (colorless).
• The red color is the result of the absence of green and blue light from white light. 
• Green color results if red and blue light are absent from white light.
• Blue color results if red and green light are absent.

Answer.3. Isoprene

Explanation:-

Natural rubber is a polymer of the molecule isoprene. Isoprene, with only five carbon atoms, is the smallest repeating unit of any natural polymer, making rubber the simplest natural polymer.

Answer.1. Gravity

Explanation:-

The Earth’s atmosphere is held in place by the pull of the Earth’s gravity. The atmosphere is pulled downwards, and it presses on everything on the Earth’s surface. It exerts a force of about 10 N on every square centimeter or 100000 N on every square meter. This is known as atmospheric pressure, and it means that everything is slightly squashed by the atmosphere. If you went to the Moon, you would find there only a very thin atmosphere because the Moon’s gravity is much weaker than the Earth’s.