Explore topic-wise InterviewSolutions in Current Affairs.

The environmental consequences of the increasing demand for energy are as following.

1. The combusion of fossil fuels is producing acid rain and damaging plants, soil & aquatic life.

2. The burning of fossil fuels is increasing the amount of greenhouse gas, CO₂ in the atmosphere.

3. The cutting down of trees from forest for obtaining fire-wood is causing soil erosion and destroying wild life.

4. The construction of hydro power plants is disturbing ecological balance.

5. Nuclear power plants are increasing radioactivity in the environment.

A. True Via a reflex with a parasympathetic efferent pathway.

B. False This leads to relaxation. 

C. True This tends to limit local over ventilation. 

D. True This is minimized normally by the warming of air in the upper airways. 

E. False This causes relaxation via beta receptors.

A. True This creates a pressure gradient between mouth and lungs. 

B. True Due to an increase in the dimensions of the thoracic cage. 

C. False It rises due to descent of the diaphragm. 

D. False It rises as inspired air replaces alveolar air. 

E. True It falls as intrathoracic pressure falls.

A. True They are present in most cells. 

B. True Lysozyme breaks down organic structures. 

C. True Lysozyme in saliva helps to destroy ingested bacteria. 

D. True The granules are examples of lysosomes. 

E. True This is responsible for decomposition of tissues after death.

A. True This is part of the cycle of respiratory sinus arrhythmia.

B. False It decreases due to expansion of the great veins. 

C. False It falls due to expansion of the thoracic cage. 

D. True Due to descent of the diaphragm. 

E. True From stretch receptors in the lung mediating the Hering–Breuer reflex.

A. True It is analogous to the sarcoplasmic reticulum in muscle cells. 

B. False The Golgi apparatus differs in structure, function and location in the cell. 

C. True As do mitochondria. 

D. True RNA is found in the ribosomes which are attached to the cytoplasmic side of the tubules in rough endoplasmic reticulum and are responsible for protein synthesis. 

E. True It is the site of hormone and enzyme synthesis.

A. True They contain an acid phosphatase. 

B. False They are stimulated to resorb bone with release of calcium ions. 

C. True Calcium is released from bone during bed rest and inactivity. 

D. True This may subject bones to increased radioactivity. 

E. True The epiphyseal plate is relatively wide during childhood.

A. True It increases as scatter increases. 

B. False This is true for two standard deviations; for one standard deviation it is 66 per cent. 

C. True Otherwise (B) above does not hold. 

D. False It is only a description of the scatter of observations. 

E. False It should not be calculated for very small numbers of observations.

Synapsis and crossing over of chromosomes occurs in PROPHASE phases of meiosis.

A. False It is beyond the resolution of the light microscope. 

B. False It consists mainly of lipid. 

C. True Fat-soluble particles dissolve easily in the lipid matrix. 

D. True These are involved in active transport. 

E. False Steroid hormones cross the membrane and act intracellularly.

A. False External triggers modulate an endogenous clock. 

B. False The hypothalamus is thought to be the location of the endogenous clock. 

C. False Adaptation takes about a week or longer. 

D. True Melatonin given at bedtime has been used to allay the circadian rhythm disturbances of sleep with jet-lag. 

E. False The peak is at night when cortisol level is minimal.

The diversity of living organisms present on the Earth is very vast. According to an estimate by researchers, it is about seven millions.
The total number of species present in the world is calculated by ecologists by statistical comparison between a species richness of a well-studied group of insects of temperate and tropical regions. Then, these ratios are extrapolated with other groups of plants and animals to calculate the total species richness present on the Earth.

M = 100g 

M = .10 kg

u = 10 cm/s

u = 10 x 10^-2 m/s

Total energy = Rotational kinetic energy 

= \(\cfrac12\) Iw² + \(\cfrac12\) mv²

\(\because\) I = \(\cfrac12\) mR²

= \(\cfrac12\) x \(\cfrac12\) mR² x w² + \(\cfrac12\) x mv²

\(\because\) v = Rw

=   \(\cfrac14 mv^2\) + \(\cfrac12 mv^2\)

= \(\cfrac{mv^2+2mv^2}4\)

= ^{\(\cfrac{3mv^2}4\)}  

^{= \(\cfrac{3\times.10\times(10\times10^{-2})^2}4\)}

^{= \(\cfrac{3\times.10\times100\times10^{-4}}4\)}

= 7.5 x 10^-4 J

Answer: More than

By connecting to the rim of wheel to the axle through the spokes the mass of the wheel gets concentrated at its rim. this increases its moment of inertia. This ensures its uniform speed.

Here T₁ = 36º C = 36 + 273 = 309 K; T₂ = 10º C = 10 + 273 = 283 K 

 COP = (T₂/T₁ - T₂) = (283/309 - 283) = 283/26 = 10.9

(i) In an elastic collision : Both momentum and kinetic energy is constant. 

(ii) In an inelastic collision : Momentum remains constant.

Rest and motion are relative. They are not absolute. A body can be in the rest or in motion w.r.t. reference frame. A man in a moving train is a rest w.r. to a co–passenger, but he is in motion w.r.t a man on the ground.

While studying the constitution of the stars, he has proved that the maximum mass that a white dwarf can have is 1.4 times the solar mass. This mass is known as chandra sekhar limit. If a star crosses this limit, it has to face a catostropic collapse. 

(∆M/M) x 100 = 2%; (∆V/V) × 100 = 3%;

Kinetic energy = (1/2) mV²

(∆K/K) x 100 = (∆M/M) × 100 + (2∆V/V) × 100

= 2 + 2(3) = 2 + 6 

= 8%

As per question,

u = 83m/s

a = -3m/s²

^{t = 2 s}

v = ?

v = u + at

v = 83 + (-3) x 2

v = 83 - 6 = 77m/s     Ans.....

To find the time after which it stops i.e. v becomes 0.

again v = u + at

0 = 83 - 3 x t

t = 83/3 = 27.66s   Ans....

To find the distance travelled before coming to rest,

v² = u² + 2ax   ( also x = ut + 1/2 at² can be used)

0² = 83² + 2(-3) x

x = - 83²/-6 = 1148.16m    Ans......

Given initial velocity,

u = 83 m/s

a = 3 m/s²

t = 2 sec

v = u + at

v = 83 + 3 x 2

after 2 sec velocity v = 89 m/s.

Elastomers does not obey Hooke's law is true 

S.I unit of the Young`s modulus Nm^-2 or Pa