OSSSC TGT Science PCM Mock Test - 4 - OTET MCQ

School and classroom environment is the place where the child's 'cognitive' development is defined in the best way. Schooling has direct effects on children's educational achievement, their acquisition of literacy, numeracy and scientific knowledge. These basic skills provide the foundation for later "subjects" such as geography, physics and foreign languages.

For Vygotsky, although biological factors constitute the necessary pre-requisite for elementary processes to emerge, socio-cultural factors are indispensable for elementary natural processes to develop. He argues for the uniqueness of the social milieu and regards socio-cultural settings as the primary and determining factor in the development of higher forms of human mental activity such as voluntary attention, intentional memory, logical thought, planning, and problem solving.

IQ is a score obtained by conducting an Intelligence Test. Intelligence involves different mental activities and abilities which include logic, reasoning, planning, and problem-solving. So IQ between 90 to 110 is considered as normal. This proves that this is normal and people having IQ between 90 to 110 can understand everything, able to do planning, reasoning, etc.
Hence, the correct answer is "Normal".

Learning is a process where we live, talk with others, learn new things which means we are interacting with others, and learning different skills like sitting, walking, eating, etc. We gain knowledge of what we are not aware of and also learn various skills that help us in the future.
Hence, the correct answer is "All of the above".

The Huygens-Fresnel principle states that every point on a wavefront is a source of wavelets. These wavelets spread out in the forward direction, at the same speed as the source wave. The new wavefront is a line tangent to all of the wavelets.
The correct answer is option B.

Ultrasound waves are a type of a sound wave which is longitudinal in nature while others are electromagnetic waves because they are transverse in nature.

To determine the resistance of a carbon resistor based on the color bands, we need to refer to the standard resistor color code. The colors represent digits and multipliers as follows:

• Green: 5
• Red: 2
• Orange: Multiplier of 10^3 (1,000)

Given the color bands: Green, Red, Orange

The resistance value is calculated as follows:

1. First digit: Green = 5
2. Second digit: Red = 2
3. Multiplier: Orange = 10^3 (1,000)

So the resistance is:

Resistance=(52)×10^3 ohms=52,000 ohms=52 kilo-ohms

Answer: The approximate resistance of the resistor is 52 kΩ.

Electromagnetic waves are not used to determine global warming.

The bright colors seen in an oil slick floating on water or in a sunlit soap bubble are caused by interference. The brightest colors are those that interfere constructively. This interference is between light reflected from different surfaces of a thin film; thus, the effect is known as thin film interference.

Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength. Scientists measure the energy of photons in electron volts (eV). X-ray photons have energies in the range 100 eV to 100,000 eV (or 100 keV). Gamma-ray photons generally have energies greater than 100 keV.

For a toroidal solenoid, B=μ0nI 
Where, B is the magnetic field, μ0 is the permeability of free space, n is the number of coils in the solenoid per length (like 2 turns per millimetre, let's say), and I is the electric current.
i.e. It does not depend upon its radius.

The Particle Model of emission and absorption is based on the idea that light is composed of discrete particles called photons, and these photons carry quantized energy. This model helps us understand how atoms and molecules interact with light by either emitting or absorbing photons during electronic transitions.

Whenever there is reflection on any surface there is refraction also beneath the surface. 
The energy of the incident beam is partially reflected and partially absorbed. 
Even a good mirror reflects nearly 80%of the incident light only. 
At normal incidence (Incident perpendicular to the surface) there is no reflection and all the light rays pass through the surface. 
When a ray passes through a denser medium and tries to enter a rarer medium and if the angle of incidence is more than the critical angle, we say there is total internal reflection. 
The total here implies that there is no refraction at all. The entire ray is refracted. 
 
Therefore when we use totally reflecting prisms, there is no energy lost due to normal incidence from air to glass and there is TOTAL (no partial refraction) reflection inside the prism. 
Thus the light is reflected almost 100% in totally reflecting prisms and hence they are preferred even though it costs high.
 

C + O₂  → CO₂ + Heat

• This is a Combination reaction because C and O₂ are combining to produce one single compound CO₂.
• This is also an Oxidation reaction because carbon is getting oxidized.
• This is also an exothermic reaction because in this reaction heat is getting released.

So Option D is correct

Hennig Brand was an alchemist looking for the philosopher's stone when he discovered phosphorus. Robert Boyle discovered it independently in 1860. Lavoisier separated metals and non-metals. Jons Jakob Berzelius used letters to signify elements.

• Centrifugation: Centrifugation is the process of separating substances of different densities using a centrifuge. In the case of separating cream from milk, centrifugation is a commonly used method.


• Process: When milk is subjected to centrifugation, the heavier components like the cream are forced to the outer edges of the centrifuge tube due to centrifugal force. This allows the cream to be separated from the milk.


• Speed and time: The speed and time of centrifugation can be adjusted to achieve better separation of cream from milk. Higher speeds and longer durations can help in obtaining a more complete separation.


• Collection: Once the centrifugation process is complete, the separated cream can be collected from the top of the tube, while the skimmed milk remains at the bottom.


• Importance: Centrifugation is a quick and efficient method for separating cream from milk without the need for complex equipment or chemicals.

Explanation:

• A. It causes cooling: This is correct. Evaporation is a cooling process because it requires heat to change liquid into vapor, which removes heat from the surrounding area.

• B. It increases with increase in humidity: This is incorrect. Evaporation decreases with an increase in humidity because the air is already saturated with moisture, leaving less room for additional water vapor.

• C. It decreases with increase in temperature: This is incorrect. Evaporation increases with an increase in temperature because higher temperatures provide more energy for the liquid molecules to escape into the air as vapor.

• D. It increases with increase in wind speed: This is correct. Wind removes the water vapor from the surface, allowing more liquid to evaporate.

Brass is a homogeneous mixture of copper and zinc.

Silver chloride, silver bromide (AgBr) and silver iodide (AgI) are the three silver "halide" compounds used in photography.

For the second period elements, L-shell is the outermost shell.

The element gallium was discovered four year's after the publication of Mendeleev's table, and it's properties matched up remarkably well with ek aluminum, fitting into the table exactly where he had predicted. 

Because sodium hydroxide is a type of chemical and when we add it to water than this will be a chemical activity.

Non - metals do not have luster. They do not reflect light from their surface ( except iodine and diamond) . So, here a lustrous now Metal is iodine.

Compound Event If an event has more than one sample point it is called a compound event, for example, S = {HH, HT} is a compound event.

Hence, the ratio is 1:2 and the division is internal.

Sgn(x) = |x|/x
► for x > 0, sgn(x) = 1
► for x = 0, sgn(x) = 0
► for x < 0, sgn(x) = -1
► Now see graphically or theoretically sgn(x) is discontinuous at x = 0

When x = 1:
y = 1 + 6 / 1
y = 1 + 6 = 7
So (1, 7) ∈ R.

Again for x = 2:
y = 2 + 6 / 2
y = 2 + 3 = 5
So (2, 5) ∈ R.

Again for x = 3:
y = 3 + 6 / 3
y = 3 + 2 = 5
So (3, 5) ∈ R.

Similarly for x = 4:

For x = 4:
y = 4 + 6 / 4
y = 4 + 1.5, but this is not a natural number (∉ N).

For x = 5:
y = 5 + 6 / 5
y = 5 + 1.2, but this is also not a natural number (∉ N).

Thus, the relation R = {(1, 7), (2, 5), (3, 5)}.

Where:
Domain of R = {1, 2, 3}
Range of R = {7, 5}