Explore topic-wise InterviewSolutions in Current Affairs.

The correct answer is

Bakelite

(CH₃)₃C – CH₂OH  represents neo-pentyl alcohol.

As we know, relative lowering of vapour pressure

\(\frac{P^0- P_s}{P^0} = x_2\)     .....(1)

where,

x₂ = mole fraction of solute

P⁰ = pure vapour pressure of water

P_s = vapour pressure of solution

\(\therefore\) Number of moles of sucrose = \(\frac 5{342} = 0.1444\)

Number of moles of water = \(\frac{1000}{18}= 55.56\)

\(\therefore\) Mole fraction of sucrose = \(\frac{0.0144}{0.0144 + 55.56} = 0.0003\)

\(\therefore\) From equation (1)

\(\frac {4.7 - P_s}{4.7} = 0.0003\)

\(4.7 - P_s = 0.00141\)

\(P_s = 4.6986 \, mm\,Hg\)

\(\therefore\) Vapour pressure of solution will be 4.6986 mm Hg.

• Solutions of liquids that do not obey Roult′s Law are called non-ideal solutions.
• Solution of those liquids whose interaction forces are different in the solution than pure liquid forms non-ideal solution.
• For example, water and ethanol.

Citric acid- Lemon
Oxalic acid- Spinach
Tartaric acid- Grapes
Lactic acid- Curd

A. False It begins to fall in the process of dark adaptation. 

B. True The initial adaptation is due more to cone adaptation. 

C. True Rods are slower to adapt but show more profound adaptation. 

D. True A previous long exposure would bleach most of the rhodopsin so more time would be needed for its resynthesis. 

E. False The pupil dilates almost immediately in the dark.

A. Option 4 Located in the foramen ovale. It is embedded in the foramen ovale membrane. 

B. Option 5 Bulges in when the oval window bulges in. Tympanic membrane movements are transmitted by the auditory ossicles to the oval window. 

C. Option 3 Dampens vibrations of the tympanic membrane. This muscle is attached to the manubrium of the malleus and when it contracts reflexly in response to an incoming sound, it tightens the tympanic membrane and damps its movements. 

D. Option 2 Dampens vibration of the oval window membrane. The stapedius muscle is attached to the stapes and pulls on it reflexly to dampen its movements in response to incoming loud noise. 

E. Option 1 Bulges out when the oval window membrane bulges in. The round window lies where the scala tympani abuts on the middle ear and by bulging out when the stapes footplate bulges in reduces the pressure changes with incoming sounds in the inner ear.

A. Option 2 Associated with bitter taste sensation. The taste buds sensing bitter tastes are located in the vallate papillae in a V-shaped area on the back part of the upper surface of the tongue. 

B. Option 4 Associated with sweet taste sensation. Taste buds that sense sweet stimuli are in the fungi form papillae on the dorsal surface towards the front of the tongue. 

C. Option 5 Associated with salt taste sensation. The taste buds at the side of the tongue respond to salt and sour taste stimuli. 

D. Option 3 Carries taste impulses serving the sensation of bitterness. The gloss opharyngeal nerve carries impulses from the posterior third of the surface of the tongue and thus serves bitter taste sensation. 

E. Option 1 Carries taste impulses serving the sensation of sweetness. The chorda tympani branch of the facial nerve carries sensory impulses from the anterior two-thirds of the tongue and thus serves the sensation of sweetness. 

A. False It decreases; taste receptors adapt to stimuli applied to them. 

B. True Stronger stimuli lead to generator potentials of greater amplitude. 

C. False There is an increase in impulse frequency, not amplitude. 

D. True All but olfactory impulses are relayed in the thalamus. 

E. True All sensory inputs send impulses via collaterals to this system.

A. True They respond to linear acceleration. 

B. True The inertia of these otoliths enables utricles to respond to linear acceleration. 

C. True These are stimulated by forces acting on the otoliths. 

D. True They are all parts of the membranous labyrinth, filled with endolymph. 

E. True Muscle tone is reflexly redistributed so that the body can withstand gravitational stresses.

A. True Cabin pressure rises above middle ear pressure. 

B. False Their area is about 20 times as great. 

C. True This ‘round window protection’ prevents damping of vibrations in the inner ear. 

D. False At this frequency, over half of the sound energy is transmitted. 

E. True Impedance matching and auditory acuity are greatest at these frequencies which are those used in normal speech.

A. Option 2 Separates scala in the inner ear. The basilar membrane on which the organ of Corti lies separates the scala media from the scala tympani. 

B. Option 4 Responsible for bony conduction of incoming sound waves. If the middle ear is completely destroyed by disease, some hearing ability remains as sound waves can be conducted through the bone of the skull to the inner ear. 

C. Option 5 Important in air conduction of incoming sound waves. The malleus, incus and stapes form a good lever system to transmit sound waves from the tympanic membrane to the round window without much attenuation. 

D. Option 3 Equalizes middle ear with atmospheric pressure. The Eustachian tube connects the middle ear to the pharynx so that the pressure on either side of the tympanic membrane is about atmospheric. 

E. Option 1 A centre for auditory reflexes. The cochlear nerve carries auditory impulses from the organ of Corti to the inferior colliculi, centres for auditory reflexes. 

A. True It is obtained using an audiometer. 

B. False In conductive deafness air conduction, but not bone conduction, is impaired. 

C. True This is an example of conductive deafness. 

D. True This can be caused by acoustic trauma, e.g. in heavy industry. 

E. False Hearing loss in the elderly (presbycusis) particularly affects higher frequencies.

A. Option 4 The sensory organ in the semicircular canals. Each semicircular canal has an ampulla whose sense organ is stimulated by movement of endolymph caused by rotary accelerations of the head in the three spatial planes in which the semicircular canals lie. 

B. Option 2 The sensory organ in the utricle. These sensory organs are stimulated by linear accelerations of the head that modify the pull of the otoliths on the hair cells of the otolith organ. 

C. Option 1 The gelatinous partition of top of the crista that closes off the ampulla. When there is movement of fluid in the semicircular canals it causes deflections of the cupula that alter the output of impulses from the underlying crista ampullaris. 

D. Option 5 The hair processes on receptor cells in the inner ear. These rod-shaped structures protrude from the hair cells and cause generator potentials when they are deformed by movement of endolymph. 

E. Option 3 The membrane structure overlying the receptor cells in the organ of Corti. This structure which overlies the organ of Corti may be involved in bending of hair cells when the basilar membrane is made to vibrate with incoming sound waves.

A. False Sound can still be transmitted by bone conduction. 

B. False These muscles damp vibration of the ossicles reflexly in response to loud noises. 

C. True Immobilization prevents the oval window vibrating and causes severe deafness. 

D. True Air pressure is atmospheric, due to the patency of the pharyngotympanic tubes connecting the pharynx to the middle ear. 

E. True Fluid (endolymph) cannot be compressed; as the oval window moves in, the round window moves out.

A. True Receptors for bitter taste predominate on the posterior dorsum of the tongue. 

B. True Recording from single taste receptors demonstrates that a single receptor can respond to more than one modality. 

C. True All acids taste sour. 

D. True Taste receptors are poor at discriminating between intensities; a concentration difference of more than 30 per cent is needed for discrimination. 

E. True Food flavour is accentuated when hot; unpleasant medicine less offensive when cold.

A. False They are modified nerve cells in the nasal epithelium. 

B. False Unlike other sensory inputs, olfactory impulses are not relayed in the thalamus. 

C. True They recognize certain molecular structures. 

D. False It is the newcomer who recognizes the smell in the room. 

E. True In their absence, food loses much of its flavour. 

A. True Harmonics are also faithfully reproduced. 

B. False Frequency and amplitude need not be related.

C. True Hence very loud sounds can damage the basilar membrane. 

D. False Low frequency vibrations travel further up the cochlea. 

E. True Speech frequencies (about 1000–3000 Hz) cause maximum vibration in this region.

A. False It faithfully reproduces the frequencies. 

B. True It is very nearly ‘critically damped’. 

C. False It bulges inwards as middle ear air is absorbed. 

D. False Reflex contraction of these muscles protects by damping vibration transmission. 

E. False Small perforations cause about 5 decibels loss; complete destruction about 50.

A. False It takes about 20 minutes. 

B. False Dilatation of the pupil contributes but regeneration of bleached receptor pigments is the main factor. 

C. False Regeneration of cone pigments plays a part. 

D. True Red light does not bleach rhodopsin. 

E. True Peripheral vision adapts better to dark conditions; rods predominate peripherally.

A. False The reverse is true. 

B. False Nerves cannot transmit impulses at the top frequencies detectable by ear, about 20 000 Hz. 

C. False At the base, the basilar membrane vibrates to high and low frequency sound waves. 

D. True High frequency sounds are damped out before they reach the apex. 

E. True This supplements the normal ossicular conduction, especially for loud sounds.

A. True Unbalanced vestibular input causes this sensation (vertigo). 

B. False In this ‘caloric’ test, reduction in nystagmus duration indicates vestibular abnormality. 

C. True Due to inappropriate information affecting brain areas controlling balance. 

D. True Compensating visual stimuli are then eliminated. 

E. True Unbalanced, excessive or reduced vestibular inputs cause nausea and vomiting as seen in sea-sickness and space-travel sickness.

A. False Less light enters the eye as the pupils constrict. 

B. False The cornea is not involved in accommodation; the increase in refractive power in the eye is due to the increased convexity of the lens caused by contraction of the ciliary muscle. 

C. True The papillary constriction restricts light rays entering the eye to the centre of the lens where there is less chromatic and spherical aberration. 

D. True Due mainly to the improvement in optical characteristic mentioned in (C) above. 

E. True To allow the object to be focused on the two foveae.

A. Option 3 Continuous jerky movements of the eyeballs. These can occur normally (physiological nystagmus) but are exaggerated in certain diseases affecting the cerebellum. 

B. Option 1 Blindness in half of the visual field. Usually caused by a lesion in one optic tract. A lesion affecting one optic nerve causes total blindness in that eye. 

C. Option 4 People who can only distinguish between two primary colours. This is one form of colour blindness; healthy people (trichromats) can distinguish between the three primary colours. 

D. Option 2 Loss of central vision with normal peripheral vision. This is due to damage to the macula. 

E. Option 5 Loss of peripheral vision with normal central vision. This is often seen in patients with lesions affecting the occipital (visual) cortex.

A. True Recession of the near point is typical of the ageing eye (presbyopia); vision at 20–30 cm deteriorates. 

B. True It affects over 70 per cent of elderly people. 

C. True It falls from 10–15 dioptres in childhood to 5–10 at 30 and to about 1 dioptre at 70. 

D. True It is a sensorineural deafness (presbycusis).

E. False High-pitched sounds are more affected.

A. True The image is inverted and reversed with respect to the object. 

B. False The point focused upon is detected at the macula (fovea). 

C. False The optic disc is medial to the fovea, so the blind spot is in the temporal part of the field of vision. 

D. False Impulses related to the temporal region of the left field of vision cross to the right at the optic chiasma. 

E. True The visual fields of the two eyes overlap, apart from the outer temporal areas.

A. False They occur when a normal person stops rotating. 

B. False Disease of the semicircular canals may cause nystagmus. 

C. True Nystagmus is an ataxia of eye fixation. 

D. True Due to cooling of fluid in the adjacent semicircular canal. 

E. False The rapid eye movements tend to make vision blurred.

A. True This allows rapid adaptation for vision in poor light. 

B. False The iris has nothing to do with the refractive power of the eye. 

C. True By permitting light to pass through peripheral, and less perfect, parts of the lens. 

D. False As with a camera, a wide aperture tends to shorten the depth of focus. 

E. False Narrowing the aperture in a camera does not result in a smaller picture.

Answer is (1) FA^–1V⁰

∵ [Young’s modulus] = \(\Big[\frac{Force}{Area}\Big]\)

⇒ [Young’s modulus] = FA^–1

⇒ [Young’s modulus] = FA^–1V⁰

(3) 1 + (52)! 

S = (2. 1 p 0 – 3. 2 p 1 + 4. 3 p 2 ......... upto 51 terms) + (1! + 2! + 3! .......... upto 51 terms) [\(\therefore\) ⁿp_n–1 = n!] 

\(\therefore\) S = (2 × 1! – 3 × 2! + 4 × 3! .... + 52.51!) + (1! – 2! + 3! ........... (51)!) 

= (2! – 3! + 4! ........ + 52!) + (1! – 2! + 3! – 4! + ...... + (51)!) 

= 1! + 52!

(1) [Ni(CN)₄]^2– 

[Ni(CN)₄]^2– 

dsp² hybridisation.

Answer is (3) If I will not catch the train, then I do not reach the station in time.

Let p denotes statement

p : I reach the station in time.

q : I will catch the train.

Contrapositive of p→ q

is ~q → ~p

~q → ~p : I will not catch the train, then I do not reach the station in time.

(2) For an integer n, if n is even, then n³ – 1 is odd. 

Contrapositive of (p → q) is ~q → ~p 

For an integer n, if n is even then (n³ – 1) is odd

(3) (I), (II) and (III)

I A_N : Be < Mg 

II IE : Be > Al 

III Charge/radius ratio of Be w less than that of Al 

IV Be, Al mainly form covalent compounds 

D ≥ 0

(a - 10)² - 4(2)(33/2 - 2a) ≥ 0

(a - 10)² - 4(33 - 4a) ≥ 0

a² - 4a - 32 ≥ 0 ⇒ a ∈ (- ∞, - 4] ∪ [8, ∞)

Answer is (1) Changing the concentration of base will have no effect on reaction (1)

Reaction 1 : SN₁

Reaction 2 : E₂

SN₁ is independent of concentration of nucleophile/base

The answer is (2) IV > III > I > II

Basic strength depends upon availability of lone pairs. Greater the resonance of lone pairs lesser the basic strength.

Answer: (2) Glucose gives schiff's test.

Open chain form of glucose is very very small, hence does not gives Schiff's test. 

Answer is 20