Indian Air Force Agniveer Science Subject Mock Test - 3 - Indian Air Force Agniveer Vayu MCQ

Let t₁ be the time taken by the ball to reach the highest point.
here, v = 0, u = 20ms⁻¹, a = −g = −10ms⁻², t = t₁
As v = u + at
∴ 0 = 20 + (−10)t₁ or t₁ = 2s
Taking vertical downward motion of the ball from the highest point to ground.
Here, u = 0, a = +g = 10ms⁻², S = 20 m + 25 m = 45 m, t = t₂

Total time taken by the ball to reach the ground = t₁ + t₂ = 2s + 3s = 5s

The relation , can only be deduced from Newton's second law, if mass remains constant with time. If mass depends on time then this relation cannot be deduced.

m : mass per unit length

∴  rate of mass leaving the the hose per sec

Rate of K.E. 

We know, the gravitational force 
,
This is valid when R is the centre to centre distance between the two masses M and m.
At a distance r < R, the mass of Earth cannot be taken as M.

The new mass (M'):
The mass of earth will be contained for a radius r. Let us assume that the mean density of the earth is ρ and that earth is a sphere with a radius equal to the distance r. We know, mass = density × volume

Therefore the gravitational force, F = 

Hence the gravitational force, F ∝ r

From the first law of thermodynamics,
we know, dU = dQ - dW ; (work done BY the system is considered +ve)
For an adiabatic process, dQ = 0, and hence, dU = -dW
For an ideal gas expansion, we see that work done
BY the system is +ve (recall the sign convention for work done), i.e., dW > 0.
Therefore, dU is less than 0, and thus, the internal energy decreases.

Potentiometer measures the potential difference using null deflection method, where no current is drawn from the cell; whereas voltmeter needs a small current to show deflection. So, accurate measurement of p.d is done using a potentiometer.

Explanation:When  bar is in motion then flux will changed hence current will be induced.

When the angle of incidence in water reaches a certain critical value, the refracted ray lies along the boundary, having an angle of refraction of 90-degrees.For any angle of incidence greater than the critical angle, light will undergo total internal reflection.

Bohr model of the hydrogen atom attempts to plug in certain gaps as suggested by Rutherford’s model by including ideas from the newly developing Quantum hypothesis. According to Rutherford’s model, an atom has a central nucleus and electron/s revolve around it like the sun-planet system.
However, the fundamental difference between the two is that, while the planetary system is held in place by the gravitational force, the nucleus-electron system interacts by Coulomb’s Law of Force. This is because the nucleus and electrons are charged particles. Also, an object moving in a circle undergoes constant acceleration due to the centripetal force.
Further, electromagnetic theory teaches us that an accelerating charged particle emits radiation in the form of electromagnetic waves. Therefore, the energy of such an electron should constantly decrease and the electron should collapse into the nucleus. This would make the atom unstable.
The classical electromagnetic theory also states that the frequency of the electromagnetic waves emitted by an accelerating electron is equal to the frequency of revolution. This would mean that, as the electron spirals inwards, it would emit electromagnetic waves of changing frequencies. In other words, it would emit a continuous spectrum. However, actual observation tells us that the electron emits a line spectrum.
 

80 = 20 × n_A ⇒ n_A = 4
80 = 40 × n_B ⇒ n_B = 2

• The electrons surrounding each atom in a semiconductor are part of a covalent bond. A covalent bond consists of two atoms "sharing" a single electron.
• Each atom forms 4 covalent bonds with the 4 surrounding atoms. Therefore, between each atom and its 4 surrounding atoms, 8 electrons are being shared.

• (A - B) is A but not B which means A excluding the intersection of A and B.
• Similarly, in the figure, the shaded region is A but not C and B which means A excluding B and C. But if B and C both are excluded from A then the intersection of A, B and C get excluded two times.
• So, we take B ∪ C to be excluded from A. Therefore the answer is A - (B ∪ C).

nPn
= n!/(n-n)!
= n!

 Largest coefficient in the expansion of (1+x)²⁴ 
= ²⁴C_24/2 
= ²⁴C₁₂

Slope of a line is not defined if the line is parallel to x axis as all points on the line have same x coordinate.

(a² + b²)×1 - (2a) × b
= a² +b² - 2ab
= (a - b)²

lim x→0 (1−cosx)/(xlog(1+x))
= lim x→0 {2sin² x/2}/[xlog(1+x)]
= lim x→0 {{2sin²x/2/(x/2)²}*/1/4}/[1/xlog(1+x)]
= lim x→0 [log(1+x)/x]1/2
= 2​

x sin(a+y) = sin y
⇒ 

Comparing it with the given value, we get

Hence, y = (1-0) - ( -1 -1) -(0 - 1) = 4

Particular solution of a given differential equationdoes not contain arbitrary constants i.e. a,b ,c etc.

Impeccable means free from fault or blame which is opposite to ‘deserving blame’.

• Culpable - Considered responsible for something bad.
• Gullible - Too willing to believe everything that other people say.
• Naive - A person or action showing a lack of experience i.e., innocent.

• Cultivate- To promote or improve the growth of a plant, crop, etc.
• Develop- To cause something to grow or change into a more advanced, larger, or stronger form.
• Teach- To pass on knowledge or instruct someone.
• Train- Teach a person or animal about a particular skill or type of behaviour through sustained practice and instruction.
• Change– Move from one to another.

So, ‘Cultivate’ is the correct synonym for ‘Develop’.

• Impede- Delay or prevent (someone or something) by obstructing them.
• Impair- Weaken or damage.
• Impose- Take advantage of someone by demanding their attention or commitment.
• Impel- force, or urge someone to do something.

Thus, the correct answer is, “If you hear loud music, it will impair your hearing.”

• Oblique- Neither perpendicular nor parallel to a given line or surface; slanting.
• Optical- A pair of glasses.
• Opaque- Not transmitting radiation, sound, heat, etc.
• Opulent- Expensive or luxurious.

Thus, the correct answer is Opaque which means “Preventing the light from traveling through”

• Bridle- The headgear used to control a horse, consisting of buckled straps to which a bit and reins are attached.
• Bridal- A newly married couple.
• Whip- A strip of leather or length of cord fastened to a handle, used for flogging or beating a person or for urging on an animal.
• Saddle- A seat fastened on the back of a horse or other animal for riding.

The suitable word for the sentence must be ‘Bridle’.
“If a racer doesn't hold the bridle accurately, he can fall.”

• Out of the given options, only 'Melifluence' is the word that has no meaning. 
• So, 'Melifluence' is the misspelt word. ​
• The correct spelling is mellifluence: The quality of sounding mellifluous; that is, the quality of sounding very smooth or pleasant.

Below is the table of confusing verbs Grind Vs Ground.

• The given sentence means that Indian Airforce has stopped flying MiG-21 aircraft.
• In the sentence given, 3rd form of verb is required in present perfect tense (has+verb3)
• NOW it is clear that the 3rd form of 'ground' shall be used.
• The 3rd form of ground is "grounded",

Correct Sentence: IAF has grounded the entire MiG-21M fleet because of a technical flaw which resulted in a series of crashes. 

• Let us explore 2nd sentence in the first paragraph:
  • "Her early work focused on a careful longitudinal study of 100 (mostly European American, middle class) preschool children.​"
• ​This sentence suggests that her early research was centred on a meticulous longitudinal study of 100 preschoolers, most of whom were middle-class European Americans.
• So, the statement I is incorrect.
• Let's have a look at the 2nd sentence of the second paragraph:
  • "They listen to concerns, give reasons for rules and allow more democratic decision making."
• This sentence suggests that Authoritative parents pay attention to complaints, provide justification for rules, and promote more democratic decision-making.
• So, the statement II is correct.

Therefore, the correct answer is Option 4.​