OSSSC TGT Science PCM Mock Test - 7 - OTET MCQ

Piaget's theory states that children actively construct their understanding of the world and go through four stages of cognitive development.

Motivation is the process of learning that defines a reason for a person to do something or the desire a person has to do something. It creates interest in learning among young learners. If learners are motivated they will perform their work efficiently and effectively and if they are not motivated to do something then it will affect their performance.
Hence, the correct answer is, 'Creates interests for learning among young learners.'

Adolescence is the stage when children become active members of the peer group. It is a transitional stage of growth and development that lies between childhood and adulthood. According to the World Health Organization, this period occurs between the age of 10 and 19. At this stage, children are more actively involved in their peer group. They share everything with their friends instead of family. They are more comfortable with their peers.
Hence, the correct answer is, 'Adolescence.'

Drift velocity, v=I/nAe
=2/(2x10^-6)x(5x10²⁶)x(1.6x10^-19)
=1.25x10^-2m/s

We know that,
Phase difference=K× path difference. K=2π/ λ.
Therefore, phase difference=(2π/ λ) ×( λ/3)=2π/3=120 degree.

Here F=f
U=-f(-because it is present in front of a convex lens)
It is given that both focal length and object distance is f .
So according to lens formula 1/F=1/v+1/u
So 1/f=(1/v)+(-1/f)
=>1/f=(1/v)-(1/f)
So (1/f)+(1/f)=1/f
=>1+(1/f)=(1/v)
=>2/f=1/v
So from here we can say that v= f/2
Hence option B is correct.
 

For real object and real Image,
(1/v)+(1/u)=(1/f)=> -(1/v)-(1/u)=-(1/f)
(1/v)+(1/u)=(1/f) => 1/v=-(1/u)+(1/f)
y=mx+c
The correct answer is option B.

Three 2Ω resistors are in series. Their total resistance =6Ω. Now it is in parallel with 2Ω resistor, so total resistance,
1/R​=1/2+1/6​=3+1/6​=4/6=2/3
R=3/2​
∴I=RV​=3/(3/2)​=3×2​/3=2A

Focal length of the lens is f = −6.0 m
u = −18 m and h = 2 m

The electromagnetic waves are not mechanical waves. There are vibrations of electric vectors and magnetic vectors in them. These vibrations do not need any particles present in the medium for their propagation. That's why electromagnetic waves do not require any medium for propagation.This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.

In Mendeleev’s periodic table, the elements are arranged in the increasing order of their atomic masses. In some places, this order has been ignored.

(a) Ar and K:  The atomic mass of argon is 40 and that of potassium is 39, But argon is placed beforepotassium in the periodic table.

(b) Co and Ni: The positions of cobalt and nickel are not in proper order. Cobalt (at. wt. = 59.9) is placed before nickel (at. wt. = 58.6).

(c) Te and I: Tellurium (at. wt. = 127.6) is placed before iodine (at. wt = 126.9).

(d) Thorium (at, wt. =232.12) is placed before protactinium (at. Wt = 231).

So, Al and Si is not the anomalous pair  of elements in the Mendeleev's periodic table.

Number of moles = Mass (in grams) / Molar mass.

• In the given reaction, the compound breaks down into two simpler products.
• Calcium carbonate is decomposed to calcium oxide and carbon dioxide.

​​​​​​​So Option A is correct

Mendeleev missed receiving the Nobel Prize by one vote. Some atomic numbers of elements on the table were refined and corrected. Elements such as sulfur and hydrogen were difficult to place within the structure of the table but Mendeleev was able to construct the table around anomalous elements.

A compound is a substance formed when two or more elements are chemically joined. Water, salt, and sugar are examples of compounds. When the elements are joined, the atoms lose their individual properties and have different properties from the elements they are composed of.

Atomic number of potassium atom is 19. Its electronic configuration is 2,8,8,1 so, its valency is 1.

The turning of any liquid into vapour is called Evaporation. The factors affecting the evaporation are:

1. Temperature. As the temperature increases, the rate of evaporation also increases.

2. Surface Area. As the Surface area increases, the rate of evaporation increases.

Hydrogen as a fuel in Sun. The source of Sun's incessant energy is hydrogen which is continuously converting to helium through nuclear fusion reaction releasing energy.

Given equation of circles are
x²+y²+6x+6y=0....(i)
and x²+y²−12x−12y=0....(ii)
Here, g1 = 3,f2 = 3, g2 = −6 and f₂ = −6
∴ Centres of circles are C₁(−3,−3) and C₂(6,6) respectively and radii are r₁ = 3√2 and r₂ = 6√2 respectively.
Now, C₁C₂ = √[(6+3)² + (6+3)²]
= 9√2
and r₁ + r₂
​= 3(2)^1/2 + 6(2)^1/2
= 9(2)^1/2
​⇒ C₁C₂ = r₁ + r₂
∴ Both circles touch each other externally.

Curved surface area of a cylinder = 2πrh

Hence, Option B is correct.

y=ax³+bx²+cx+5
(−z,0) lies on curve y=ax³+ bx² + cx + 5d
⇒ 0= −8a + 4b − 2c + 5.....(1)
Also at (−2,0) curve touches x-axis ie dy/dx at (−2,0) is 0 
∴ dy/dx=3ax²+2bx+c
dy/dx (−2,0)=0=12a = −4b + c....(2)
Since curve crosses y-axis at Q, x-coordinate of point Q must be zero 
⇒ y = 0 + 0 + 0 + 5
⇒y = 5
∴ coordinate of Q = (0,5)
According to Question  dy/dx =3 at Q(0,5)
⇒ 3= 0 + 0 + c
⇒ c = 3
putting the value of c in eqn(1) & eq n(2)and gurthare solving we get 
a=−1/2 & b=-3/4
​∴Eqn of cover is y = −(x³) / 2−3/4x² + 3x + 5