Bihar STET Paper 1 Science Mock Test - 7 - Bihar PGT/TGT/PRT MCQ

The above reaction is an example of displacement reaction as in the above reaction the elemental Zinc is displacing hydrogen from the compound of hydrochloric acid which is released in the form of hydrogen gas. The Zinc then combines with Chlorine to form Zinc Chloride.

Plants respond to stimuli like touch by utilizing electrical-chemical signals to communicate between cells. This mechanism allows plants to react to various stimuli without the need for a nervous system or muscles, showcasing their unique adaptation to environmental cues.

The metal that does not react with oxygen is Au (Gold).

The detailed explanation is as follows:

• Cu (Copper): Copper reacts with oxygen in the air to form copper oxide. This can be seen as the greenish color on the surface of copper objects.


• Au (Gold): Gold is a noble metal and does not react with oxygen under normal conditions. It is highly resistant to corrosion and oxidation.


• A and B: This option includes both copper and gold. Since copper reacts with oxygen and gold does not, this option is incorrect.


• Fe (Iron): Iron readily reacts with oxygen to form iron oxide, commonly known as rust. This is why iron objects can rust when exposed to moisture and air.

Therefore, the correct answer is option B: Au (Gold).

J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model. In Thomson's model, the atom is composed of electrons (which Thomson still called “corpuscles,” though G. J.

Acids possess sour taste and turn blue litmus paper red.

Colloids
A colloid is a mixture in which small particles of one substance are dispersed evenly throughout another substance. The particles in a colloid are larger than those in a solution but smaller than those in a suspension. Colloids can be found in various forms, including liquids, gels, and solids.
Identifying the Colloid
To determine which of the given options is a colloid, we need to understand the characteristics of a colloid and analyze each option accordingly.
A: Aluminium paint
- Aluminium paint is a mixture of tiny aluminum particles dispersed in a liquid medium, usually oil or water.
- The aluminum particles in the paint are larger than those in a solution but smaller than those in a suspension.
- Therefore, aluminium paint is a colloid.
B: Blood
- Blood is a complex mixture of cells, proteins, and other substances suspended in plasma.
- The cells and proteins in blood are larger than those in a solution but smaller than those in a suspension.
- Therefore, blood is a colloid.
C: Milk
- Milk is a mixture of water, fats, proteins, and other substances.
- The fats and proteins in milk form small particles that are dispersed throughout the liquid.
- These particles are larger than those in a solution but smaller than those in a suspension.
- Therefore, milk is a colloid.
D: All
- Since all three options (aluminium paint, blood, and milk) meet the characteristics of a colloid, the correct answer is D: All.
Conclusion
In summary, all of the given options (aluminium paint, blood, and milk) are colloids. They are all mixtures in which small particles of one substance are dispersed evenly throughout another substance.

The uterus is a crucial organ in the female reproductive system responsible for supporting the development of the baby. It is a bag-like structure where the embryo develops into a fetus during pregnancy until birth.

The majority of carbon dioxide molecules (85 percent) are carried as part of the bicarbonate buffer system. In this system, carbon dioxide diffuses into the red blood cells. Carbonic anhydrase (CA) within the red blood cells quickly converts the carbon dioxide into carbonic acid (H₂CO₃). Carbonic acid is an unstable, intermediate molecule that immediately dissociates into bicarbonate ions (HCO₃ -) and hydrogen (H⁺) ions. Since carbon dioxide is quickly converted into bicarbonate ions, this reaction allows for the continued uptake of carbon dioxide into the blood, down its concentration gradient. It also results in the production of H+ ions. If too much H+ is produced, it can alter blood pH. However, hemoglobin binds to the free H+ ions, limiting shifts in pH. The newly synthesized bicarbonate ion is transported out of the red blood cell into the liquid component of the blood in exchange for a chloride ion (CI_-). This is called the chloride shift. When the blood reaches the lungs, the bicarbonate ion is transported back into the red blood cell in exchange for the chloride ion. The H⁺ ion dissociates from the hemoglobin and binds to the bicarbonate ion. This produces the carbonic acid intermediate, which is converted back into carbon dioxide through the enzymatic action of Ca. The carbon dioxide produced is expelled through the lungs during exhalation.

Gases released in biogas are methane, carbon dioxide, hydrogen and, hydrogen sulfide .but the production of methane is highest (75%). It is the main constituent of biogas.

The correct option is D.
The atomic size is of the order of 10⁻⁸
cm or 10⁻¹⁰ m or one angstrom unit.
On the other hand, the radius of an atomic nucleus is of the order of 10⁻¹³
cm or 10⁻¹⁵ m or one Fermi unit.

Urea is a waste product and is not reabsorbed; instead, it is excreted in the urine. Glucose, amino acids, and salts are selectively reabsorbed.

An oxidizing agent, or oxidant, gains electrons and is reduced in a chemical reaction. Also known as the electron acceptor.

It is known as boiling. And that temperature known as boiling temperature. When you change a liquid in to gas this process is called vaporization. The process by which a substance gets converted from liquid to gas under low temperature or heating is called evaporation.

Changes of state are physical changes in matter. They are reversible changes that do not involve changes in matter’s chemical makeup or chemical properties. Common changes of state include melting, freezing, sublimation, deposition, condensation, and vaporization.

Neurons have a single long part called an axon, which transmits nerve impulses away from the cell body.

One atomic mass unit is defined as one-twelfth of the one-carbon of one carbon - 12 atom because C - 12 is chosen as the standard form.

The pressure of the expanded urinary bladder triggers the urge to pass urine.

An olfactory indicator is a material whose smell varies reliant on whether it is mixed with an acidic or basic solution. Olfactory indicators mainly used in laboratory to test whether a solution is a base or an acid. Onion is an example of olfactory indicators. 

Cartilage is not found in the kidney. It is a connective tissue that provides support and flexibility and is found in various parts of the body, including the nose, ear, and larynx.

Covalent bonds are formed by sharing of electrons.

The correct answer is (b) 1 g of hydrogen and 8 g of oxygen. This is because water (H2O) consists of two hydrogen atoms and one oxygen atom. By mass, hydrogen contributes approximately 11.1% and oxygen contributes approximately 88.9% to the mass of water. Thus, from 9g of water, we get approximately 1 g of hydrogen and 8 g of oxygen.

When iron and sulphur are heated at high temperature:
- Black coloured FeS is formed: When iron and sulphur are heated at high temperature, they react to form iron sulphide (FeS) which is black in color. This reaction is a synthesis reaction where iron and sulphur combine to form a new compound.
- Mixture of iron and sulphur is obtained: This statement is incorrect. Heating iron and sulphur at high temperature does not result in a simple mixture of iron and sulphur. Instead, a chemical reaction takes place and a new compound, iron sulphide, is formed.
- Yellow coloured iron sulphide is formed: This statement is incorrect. Iron sulphide (FeS) formed from the reaction of iron and sulphur is black in color, not yellow.
- They do not heat: This statement is incorrect. Iron and sulphur can be heated at high temperatures to initiate a chemical reaction between them.
Therefore, the correct answer is option A: Black coloured FeS is formed.

2NaCl + 2H₂O → 2NaOH + H₂ + Cl₂
(Chlor-alkali process)

The correct answer is c as all the statements are false about the solubility. 

A teacher can be satisfied with his quality of teaching if he/she is able to get counter questions from students on the concepts which have been taught in class. This ensures that the student is able to understand the concept and shows interest in the subject.

A gifted child is one whose IQ is above 130. He/she derives many creative ideas, explores many possible solutions for a single problem, thinks in a divergent way. always have a curiosity to know about new things, always brings something unusual and entertaining beyond the level of thinking at the same age children. All these qualities are found in gifted children. 
Hence, the correct answer is, 'Fighting with others.'

The main aim of CCE is to evaluate every aspect of the child during their presence at the school. This is believed to help reduce the pressure on the child during/before examinations as the student has to sit for multiple tests throughout the year, of which no test or the syllabus covered is repeated at the end of the year, whatsoever. The CCE method is claimed to bring enormous changes from the traditional chalk and talk method of teaching, provided it is implemented accurately. As a part of this new system, student's marks have been replaced by grades which are evaluated through a series of curricular and extra-curricular evaluations along with academics. The aim is to reduce the workload on students and to improve the overall skill and ability of the students by means of evaluation of other activities.

Some games, like some real situations, are intensely competitive, where an individual or a team has to compete against someone else. In case of a team, cooperation among members is of paramount importance to reach the objective or to deal with any issue effectively, So, both these skills are required to excel in different real life situations. A teacher must know what would bring out the best in the students and ensure the same.

Agrobiology is the art of plant nourishment and development in connection to soil conditions, particularly to decide approaches to increment crop yields. Agrobiology is for the most part related with: animal health and welfare, plant nutrition and health and organic agriculture.

∠DAC = ∠B + ∠C
(Exterior angle prop. of a Δ ABC)
According to question,
130° = 2A + 3A
5A = 130°
A = 26°
∴ ∠B = 52°; ∠C = 78°