Practice Test - NEET MCQ

Projectile motion is a natural phenomenon it is due to the gravity in earth surface .it doesn't need any external force .The flight seems to be same as an projectile motion but it differs as an external force is applied which is the aircraft engine which pulls the craft forward and hence oppose the force of gravity.

Ship 2 gets hit first. The time of flight only depends on the y-component of motion, not the x-component.  The higher you throw something up in the air, the more time it spends in the air.  It can also be shown from equation-

y=v_0y t – ½ g t²=0  

    v_0y for projectile μ1 is greater than for μ2.

We know that the horizontal range for any projectile motion let say R = 2u².sin 2a /g
Where u is initial speed, and a is the angle at which the particle is thrown, which is responsible for direction. So in between the possible range of a that is 0 - 90, there are maximum two equal values of sin 2a, thus the maximum number of directions for the same or equal range are 2.

Key points:

• The stone has a mass of 0.1 kg.
• The train is moving at a constant velocity (1 m/s).
• The stone is at rest relative to the train.
• We are neglecting air resistance.

Since the stone is at rest relative to the train and the train is moving with a constant accleration, the net force acting on mass .
F= ma 
F =0.1 x 1 N
F = 0.1 N

• Force is required to start a stationary object and to stop a moving object due to inertia. 
• Inertia is a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.
• This is also called law of inertia or newton's first law of motion.
• Newton's first Law:
  

The amount of mass or energy entering a control volume does not have to be equal to the amount of mass or energy leaving during an unsteady-flow process.It is mostly converted to internal energy as shown by a rise in the fluid temperature.

2CO + O2 ------------> 2CO₂
Atomic wt of C =12 kg or gms, Atomic wt of O = 16 kg or gms
2(12 + 16) kg of CO + 32 kg of O2 -----------> 2(12+32) kg of CO₂
56 kg of CO + 32 kg of O₂ -------> 88 kg of CO₂
For, 1kg of CO + 32/56 kg of O₂ ---------> 88/56 kg of CO₂
Therefore, 1kg of CO requires 32/56 or 4/7 kg of oxygen to produce 88/56kg or 11/7 kg of CO2

The expression for the change in internal energy is given by,
ΔU=q+w
q = heat absorbed = 200 J
w = work done = −P x V
=−2×10⁵ × 500×10⁻⁶
= −100 N - m
ΔU=200−100J= 100 J
Hence, the correct option is C.

Electron rich species are called lewis base. Among the given, BF₃ is an electron deficient species, so have a capacity of electrons accepting instead of donating that's why it is least likely to act as a lewis base. It is a lewis acid. 

Acid ⇋ Conjugate Base  +  H⁺
By this definition,
HNO2 ⇋ NO₂^- + H⁺
CH₃NH₃+ ⇋ CH₃NH₂ + H⁺
C₆H₅COOH ⇋ C₆H₅COO^- + H⁺
H₃O⁺ ⇋ H₂O + H⁺
We can see that the conjugate base of H₃O+ is H₂O. But it is given that OH^- is the C.B. So option d is incorrect.

B₂H₆ is an electron deficient species. Soit will act as Lewis acid.

H₂CO₃ is formed by dissolution of CO₂ into water. This dissociates into H+ and HCO^3-. This is the first dissociation of H₂CO₃. Since HCO^3- has another H, it again dissociates to H⁺ and CO₃^2-. H+ obtained attacks the lone pair of H₂O to form H₃O⁺. So H₃O⁺, HCO^3-, CO₃^2-, H₂CO₃ are present in water when CO₂ is dissolved in  water.

The pericarp is the part of the fruit that develops from the ovary wall. After fertilization, the ovary undergoes changes and develops into a mature fruit. The pericarp consists of three layers: the exocarp, mesocarp, and endocarp.
So the correct answer is A

The outer layer is called testa and the inner layer is called tegmen. There is a scar on the seed coat through which the developing seed was attached to the fruit. This scar is called hilum.
So the correct answer is C

Actinomorphic flowers are radially symmetrical, they are able to be divided into similar halves in more than one vertical plane.
Zygomorphic flowers are bilaterally symmetrical,they can be divided into similar halves in only one plane.
Cyclic is a type of floral organ arrangement, the floral organs are arranged in regular whorls at the node of the thalamus.
Heteromorphic is a type of incompatibilty, same species produce more than one morphological type of flower.
So the correct answer is C

POLYGAMY ⇒ The condition of bearing some flowers with stamens only, some with pistils only, and some with both, on the same or different plants. 

BISEXUAL ⇒ The flower having both male and female reproductive organ on the same plant. 

DIOECIOUS ⇒ Both male and female plants may have flowers, but one will have "male" flowers and the other "female" flowers.

UNISEXTUAL ⇒ The flower which has only one essential worl either male or female.
So the answer is D

In palmately reticulate venation there is more number of main veins arising from the base of the leaf. So it is otherwise called as multicostate type. Palmately reticulate or multicostate venation is again divided into two they are:

(i) Palmately reticulate (Divergent)

(ii) Pinnately reticulate (Convergent).
So the correct answer is C

Liliaceae is the characteristics representative of monocotyledonous plants. Floral characters of this family are: tricarpellary, actinomorphic, polyandrous, superior ovary, axile placentation.
So the correct answer is D

In plants respiratory organs in stem is called lenticels. They are located as pores in the bark of plants.

Separate xylem and phloem bundles are found in dicotyledonous roots. This kind of vascular bundle is called radial vascular bundle.

The tissues involved in secondary growth are the two lateral meristems namely, vascular cambium and cork cambium.

In conjoint type of vascular bundles,the xylem and phloem are situated at the sameradius of vascular bundles. Such vascularbundles are common in stems and leaves. Theconjoint vascular bundles usually have thephloem located only on the outer side of xylem.

The abaxial epidermis generally bears more stomata than the adaxial epidermis.

Quiescent centre is a small group of cells with low mitotic activity. It is found at the tips of growing roots in the root meristem.

The wood is actually a secondary xylem. There are different types of wood on the basis of their composition and time of production.

Xylem is a complex tissue, which consists of four kinds of cells. These cells are tracheid, vessels, xylem parenchyma and xylem fibers. Companion cell is part of phloem tissue.

Frogs use their skin for cutaneous respiration when they are in water, absorbing oxygen directly from the dissolved oxygen in the water through their moist skin.

Frogs do not have a tail; they have a head and trunk directly connected, without a distinct neck or tail.

Digestion in frogs primarily occurs in the intestine, where final digestion and absorption of nutrients take place after initial processing in the stomach.

The skin of a frog is smooth and slippery due to the presence of mucus. The skin has a moist characteristic which is maintained. A frog does not drink water but has the ability to absorb water through its skin.