Silverlineprestigeschool PCB/Code-B

SilverLinePrestigeSchool PCB/code-B

PART – A PHYSICS

Two particles A and B initially at rest move towards each other under a mutual force of attraction. At the instant when the speed of A is v and the speed of B is 2v, the speed of centre of mass of the system is

(a) zero(b) v

A disc is rolling (without slipping) on a horizontal surface. C is its center and Q and P are two points equidistant from C. Let vp, vQ and vc be the magnitude of velocities of points P, Q and C respectively, then

(a) vQvcvp

(b) vQvcvp

(d) vQvcvp

A circular disc of radius R and thickness has moment of inertia I about an axis passing through its centre and perpendicular to its plane. It is melted and recasted into a solid sphere. The moment of inertia of the sphere about its diameter as axis of rotation is

(a) I(b)

One quarter sector is cut from a uniform circular disc of radius R. This sector has mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

(a) MR2

(b) MR2 90

(d) MR2

A thin wire of length L and uniform linear mass density  is bent into a circular loop with centre at O as shown. The moment of inertia of the loop about the axis XX is

(a)

(b) 90

(d)

Two discs of same thickness but of different radii are made of two different materials such that their masses are same. The densities of the materials are in the ratio 1 : 3. The moments of inertia of these discs about the respective axes passing through their centres and perpendicular to their planes will be in the ratio

(a) 1 : 3(b) 3 : 1

Let I be the moment of inertia of a uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle  with AB. The moment of inertia of the plate about the axis CD is then equal to

(a) I(b) I sin2 

Two point masses of 0.3 kg and 0.7 kg are fixed at the ends of a rod of length 1.4m and of negligible mass. The rod is set rotating about an axis perpendicular to its length with a uniform angular speed. The point on the rod through which the axis should pass in order that the work required for rotation of the rod is minimum, is located at a distance of

(a) 0.4 m from mass of 0.3 kg

(b) 0.98 m from mass of 0.3 kg

(d) 0.98 m from mass of 0.7 kg

A pulley of radius 2m is rotated about its axis by a force F = (20t – 5t2) newton (where t is measured in seconds) applied

tangentially. If the moment of inertia of the pulley about its axis of rotation is 10kg m2, the number of rotations made by the pulley before its direction of motion if reversed, is

(a) Less than 3

(b) More than 3 but less than 6

(d) More than 9

A solid cylinder is rolling down on an inclined plane of angle . The coefficient of static friction between the plane and cylinder is s. The condition for the cylinder not to slip is

(a) tan  3s(b) tan  > 3s

A particle undergoes uniform circular motion. About which point of the circle, will the angular momentum of the particle remain conserved

(a) Centre of the circle

(b) On the circumference of the circle

(d) Outside the circle

Consider a body, shown in figure, consisting of two identical balls, each of mass M connected by a light rigid rod. If an impulse J = MV is imparted to the body at one of its ends, what would be its angular velocity

M M

J = MV

(a) V/L(b) 2V/L

A thin circular ring of mass M and radius r is rotating about its axis with a constant angular velocity . Two objects each of mass m are attached gently to the opposite ends of a diameter of the ring. The ring will now rotate with an angular velocity

(a) (b)

A straight rod of length L has one of its ends at the origin and the other at x = L. If the mass per unit length of the rod is given by Ax where A is constant, where is its mass centre?

(a) L/3(b) L/2

A mass m is moving with a constant velocity along a line parallel to x-axis. Its angular momentum with respect to origin or z-axis is

(a) zero

(b) remains constant

(d) Goes on decreasing

An equilateral triangle ABC formed from a uniform wire has two small identical beads initially located at A. The triangular is set rotating about the vertical axis AO. Then the beads are released from rest simultaneously and allowed to slide down, one along AB and the other along AC as shown. Neglecting frictional effects, the quantities that are conserved as the beads slide down, are

B a C

(a)Angular velocity and total energy

(kinetic and potential)

(b)Total angular momentum and total

energy

(c)Angular velocity and moment of

inertia about the axis of rotation

(d)Total angular momentum and

moment of inertia about the axis of

rotation

A cubical block of side a is moving with velocity v on a horizontal smooth plane as shown. It hits a ridge at point O. The angular speed of the block after it hits O is

(a) 3v/4a a

(b) 3v/2a v

(d) zero O

A disc of mass M and radius R is rolling with angular speed  on a horizontal plane as shown. The magnitude of angular momentum of the disc about the origin O is

(a) MR2  y

(b) MR2 

(d) 2 MR2  M

O x

A child is standing with folded hands at the centre of a platform rotating about its central axis. The kinetic energy of the system is K. The child now stretches his arms so that the moment of inertia of the system doubles. The kinetic energy of the system now is

(a) 2 K(b) K/2

Two solid cylinders P and Q of same mass and same radius start roling down a fixed inclined plane from the same height at the same time. Cylinder P has most of its mass concentrated near its surface, while Q has most of its mass concentrated near the axis. Which statement (s) is (are) correct

(a) Both cylinders P and Q reach the

ground at the same time

(b) Cylinder P has larger linear

acceleration than cylinder Q

ground with same translation

kinetic energy

(d) Cylinder Q reaches the ground with

larger angular speed

An asteroid of mass m is approaching earth, initially at a distance of 10 Re with speed vi. It hits the earth with a speed vf (Re and Me are radius and mass of earth), then

(a) = +

(b) = +

(d) = +

A thin uniform annular disc (see figure) of mass M has outer radius 4R and inner radius 3R. The work required to take a unit mass from point P on its axis to infinity is

(a) (b)

A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of earth

(a)The acceleration of S is always

directed towards the centre of the

earth

(b)The angular momentum of S about

the centre of the earth changes in

direction but its magnitude remain

constant

(c)The total mechanical energy of S

varies periodically with time

(d)The linear momentum of S remains

constant in magnitude

A mass M is split into two parts, m and (M – m), which are then separated by a certain distance. What ratio of m/M maximizes the gravitational force between the two parts

(a) 1/3(b) 1/2

Suppose the gravitational force varies inversely as the nth power of distance. Then the time period of a planet in circular orbit of radius R around the sun will be proportional

(a) R(b) R

A system or binary stars of masses mA and mB are moving in circular orbits of radii rAand rB respectively. If TA and TB are the times periods of masses mA and mB respectively then

(a) (b) TA > TB (if rA > rB)

(d) TA = TB

A simple pendulum has a time period T1 when on the earth’s surface and T2 when taken to a height R above the earth’s surface, where R is the radius of the earth. The value of T2/T1 is

(a) 1(b)

A body mass m is taken from earth surface to the height h equal to radius of earth, the increase in potential energy will be

(a) mgR(b) mgR

An article satellite moving in a circular orbit around the earth has a total (kinetic + potential) energy E0. Its potential energy is

(a) – E0(b) 1.5 E0

A geostationary satellite orbits around the earth in a circular orbit of radius 36000 km. Then, the time period of a satellite orbiting a few hundred kilometres above the earth’s surface (REarth = 6400 km) will approximately be

(a) 1/2 h(b) 1 h

PART – B CHEMISTRY

Compressibilities (Z) of nitrogen gas at three temperatures 0º C, – 50º C & 300º C were drawn against pressure as shown in figure

Z A

1.00

0.80

O P (Bar)

Which is correct matched

(a) A = 300º C, B = – 50º C, C = 0º C

(b) A = – 50º C, B = 0º C, C = 300º C

(d) A = 300º C, B = 0º C, C = – 50º C

Which of the following is an intensive properties

(a) Enthalpy

(b) Molar heat capacity

(d) Entropy

For the following equilibrium at 298 K

ΔGº are as follows.

(i) A B ΔGº = – 50 kJ

(ii) M N ΔGº = – 100 kJ

(iii) P Q ΔGº = 250 kJ

(iv) R S ΔGº = 400 kJ

Which of the following equilibrium has

higher value of equilibrium constant(KC)

(a) (i)(b) (ii)

At 300 Ktemp.

pressure in the

shown flask was

CH4(g) found to be 2.4 atm.

If aqueous tension

at 300 K is 0.4 atm

1 lit. water then mass of CH4(g)

V = 10 lit in flask is

approximately –

(a) 11.85 gm (b) 10.42 gm

In a 10 lit flask 7.1 gm of chlorine gas was taken at 300 K. If at 300 K degree of dissociation of Cl2 is 50%.

Cl2(g) 2 Cl(g)

The pressure in the flask is –

(a) 1.5 R (b) 3.0 R

(R is gas constant)

ΔHºf (standard enthalpy of formation) is zero for

(a) H2O(l)(b) H2O(s)

According to second law of thermodynamics for a spontaneous process.

(a) ΔSsystem = ΔSsurrounding

(b) ΔSsystem > ΔSsurrounding

(d) ΔSsystem + ΔSsurrounding > 0

At 300 K Vrms of H2 gas is 4 times to Vrms of gas ‘A’ at 600 K. M.wt of ‘A’ is –

(a) 16(b) 32

On increasing pressure from 1 atm to

2 atm, kp of which of the following

equilibrium (s) will increase.

(1) 2HI(g) H2(g) + I2(g)

Kp =

(2) PCl5(g) PCl3(g) + Cl2(g)

Kp =

(3) N2O4(g) 2 NO2(g) Kp =

(a) 2 & 3(b) 1,2

In a 10 lit flask 2 mol of PCl5(g) were

taken at 300 K. If at 300 K PCl5(g) has

a degree of dissociation of 50%,

The total pressure at equilibrium is –

(a) 30 R (b) 50 R

(R  gas constant)

At 400 K and 2 bar pressure iodine

vapours contain 50% iodine atoms.

Kp of equilibrium

I2(g) 2I(g) is –

(a) 1 bar (b) 2 bar

Which of the following reaction show

standard enthalpy of formation of

HBr(g)

(a) H2(g) + Br2(g) → 2HBr(g)

(b) H2(g) + Br2(g) → HBr(g)

(d) H2(g) + Br2(l) → HBr(g)

In which case density of gas would be maximum.

(a) 1mol of H2(g) in a 20 lit flask at

300 K temperature

(b) 1 mol of CO2(g) in 50 lit flask at

300 K temperature

500 K temperature

(d) 1 mol of NH3(g) in 10 lit flask at

500 K temperature

The value of vanderwaal gas constant ‘a’ changes with

(a) changing temperature

(b) changing pressure

(d) ‘a’ of a gas remain constant.

Equal masses of H2, CH4 and O3 were taken in a sealed flask at 400 K. The partial pressure of CH4 was found to be one atm. Partial pressure of H2 & O3 would be respectively

(a) 8 atm & 0.33 atm

(b) 12 atm & 0.50 atm

(d) 3 atm & 0.25 atm

Critical temperature of a gas is 100 K The temperature at which second virial constant of the gas would become zero is

(a) 100 K(b) 337.5 K

At 400 K in a sealed flask some NH3 gas was taken at a pressure of 1.5 bar. In this flask some solid NH4Cl was added. If at 400 K Kp of reaction.

NH4Cl(s) NH3(g) + HCl(g)

is 1 bar2. Total pressure in flask at

equilibrium is –

(a) 1.0 bar (b) 1.5 bar

At 300 K enthalpy of combustion of CO(g) is –150 kJ/mol. Change in internal energy of the combustion of carbonmono oxide is approximately –

(a) –151.2 kJ/mol

(b) –148.8 kJ/mol

(d) –24.6 kJ/mol

‘X’ ‘Y’

‘A’ ‘B’

In two identical flask shown above at

300 K 1 mol of an ideal gas ‘X’ in

flask ‘A’ and 1 mol of a real gas ‘Y’ in

flask ‘B’ were taken. Which of the

following is correct.

(PX Pressure in flask ‘A’,

PY = Pressure in flask ‘B’)

(a) PX = PY(b) PX > PY

For an endothermic reaction

A(S) B(S) + O2(g)

which of the following graph is correct

(a)

ln Po2

(b)

ln Po2

(c)

ln Po2

(d)

ln Po2

At 400 K vapour density of N2O4(g) was found to of vapour density of undissociated N2O4(g). The degree of dissociation of N2O4(g) at 400 K is

N2O4(g) 2NO2(g)

(a) (b)

12 gm of carbon (graphite) was combusted with 28 gm of O2. If no reactant was left after the reaction then total amount of heat released is –

(ΔHºf CO(g) = – 200 kJ/mol.

ΔHºf CO2(g) = – 320 kJ/mol)

(a) 365 kJ(b) 185 kJ

At 600 K in a closed flask PCl5(g) was taken. The following two equilibrium occurredsimultaneously

PCl5(g) PCl3(g) + Cl2(g) Kp = 1 Bar

Cl2(g) 2Cl(g) Kp = 4 Bar

If at equilibrium, pressure of PCl3 and

pressure of PCl5 are same than the

pressure Cl(g) at equilibrium is –

(a) 1 Bar(b) 2 Bar

In this pressure volume graph for

1 mol of a gas.

(1)

(2)

(3)

Which is correct

(a) T1 = T2 > T3(b) T1 = T2 < T3

In a 100 M3 balloon of mass W1 kg, helium gas of mass W2 kg is present. If density of air is 1.5 gm/lit at given temperature. The pay load at this temperature is.

(a) 150 – (W1 + W2)kg

(b) 1500 – (W1 + W2)kg

(d) 150000 – (W1 + W2)kg

At 400k which of the following gas molecules show greater kinetic energy.

(a) H2

(b) He

(d) all have same value

An open flask initially at 400 K was heated to a temperature at which rd of its air expelled out. The temperature to which flask was heated is –

(a) 133.3 K(b) 533.3 K

10 moles of a mixture of hydrogen and oxygen gases at a pressure of 1 atm at constant volume and temperature, react to form 3.6 g of liquid water. The pressure of the resulting mixture will be closest to

(a) 1.07 atm(b) 0.97 atm

The volume of oxygen at STP required to burn 2.4 g of carbon completely is

(a) 1.12 L(b) 8.96 L

At room temperature, the average speed of Helium is higher than that of Oxygen by a factor of

(a) 2(b) 6/

PART – C BIOLOGY

Blood group is due to :

(a) specific antigen on the surface of

WBC

(b)specific antibodies on the surface of RBC

(c)specific antigen on the surface of RBC

(d)type of haemoglobin present in

blood.

Give below are the figures of blood

vessels. Identify them and select the

correct option.

A BC

(a)Capillary vein Artey

(b)Artery Capillary Vein

(c)Vein Capillary Artery

(d) Vein Artery Capillary

Match the excretory organ with animal

in which it is found.

Excretory organ Animal

A.Nephridia(i) Planaria

B.Flame cells(ii) Prawns

C.Antennal glands(iii) Earthworm

D.Tubules(iv) Cockroaches

(a)A - (iii), B - (i), C - (ii), D - (iv)

(b)A - (iii), B - (iv), C - (i), D - (ii)

(c)A - (ii), B - (iii), C - (i), D - (iv)

(d)A - (ii), B - (i), C - (iii), D - (iv)

Select the stage which shows

Anaphase - II

Which one of the following pairs of

food components in humans reaches

the stomach totally undigested?

(a)Starch and fat

(b) Fat and cellulose

(c)Starch and cellulose

(d) Protein and starch

Crypts of Lieberkuhn are present in

(a)pancreas and secrete pancreatic

juice

(b) small intestine and secrete

digestive enzymes

(c)stomach and secrete dilute HCI

(d) stomach and secrete trypsin.

The given figure is schematic break-

up of the phases/stages of cell cycle.

Which one of the following is the

correct indication of the stage/phase

in the cell cycle?

(a)C - karyokinesis

(b)D - synthetic phase

(c)A - cytokinesis

(d)B - metaphase

The given figure is the representation

of a certain event at a particular

stage of type of cell division.

Which is the stage?

(a)Prophase-I during meiosis

(b)Prophase-II during meiosis

(c)Prophase of mitosis

(d)Both prophase and metaphase of

mitosis

Based on their position in the given

figure, identify the correct osmolarity of

A, B and C in the given data.

(a)A - 1200 mOsmol L–1; B - 400 mOsmol L–1; C - 600 mOsmol L–1.

(b)A - 400 mOsmol L–1; B - 1200 mOsmol L–1; C - 600 mOsmol L–1.

(c)A - 400 mOsmol L–1; B - 600 mOsmol L–1; C - 1200 mOsmol L–1.

(d)A - 600 mOsmol L–1; B - 400 mOsmol

L–1; C - 1200 mOsmol L–1.

In mitochondria, cristae act as sites for

(a)protein synthesis

(b) breakdown of macromolecules

(c)oxidation - reduction reaction

(d) phosphorylation of flavoproteins.

Predominant from of lipid presrent in

biomembranes are

(a)triacylglycerols

(b) cholesterol

(c)free fatty acids

(d) phospholipids.

Progesterone is secreted by which of

the following glands?

(a)corpus luteum

(b)placenta

(c)mature graaffian follicle

(d) prothoracic gland.

Smooth endoplasmic reticulum is

found abundantly in

(a)lipid and steroid secreting cells

(b)protein secreting cells

(c)egg cells

(d) spermatocytes.

Uni directional transmission of a

nerve impulse through nerve fibre is

due to the fact that.

(a)nerve fibre is insulated by a

medullary sheath

(b)Na+ pump starts operating only at

the cyton and then continues into

the nerve fibre

(c)neuro transmitters are released by

dendrites and not by axon

endings

(d)neuro transmitters are released

by the axon endings and not by

dendrites

The correct route through which

pulse-making impulse travels in the

heart is

(a)SA node Purkinje fibre bundle of

His AV node heart muscles

(b)SA node AV node bundle of His

Purkinje fibres heart muscles

(c)AV node bundle of His SA node

Purkinje fibres heart muscles

(d)AV node SA node Purkinje fibres

bundle of His heart muscles.

Sarcomere structural and functional

unit of myofibril and area between.

(a)I and I band

(b) Z to Zline

(c)I band to Z line

(d) A to I band.

Glucose and amino acids are

reabsorbed in the

(a)proximal tubule

(b) distal tubule

(c)collecting duct

(e) loop of Henle.

Diabetes insipidus occurs due to the

hyposecretion of

(a)thymosine(b) oxytocin

The term ‘totipotency’ refers to the

capacity of a

(a)cell to generate whole plant

(b) bud to generate whole plant

(d) cell to enlarge in size.

Which one of the following graphs shows the relationship between the rate on an enzymatic activity and substrate concentration (S)?

Read the given statements and select

the correct option.

Statement 1: Chloroplast and

mitochondria are semiautonomous

bodies.

Statement 2 : Chloroplast and

mitochondria have their own DNA andprotein synthesizing machinery.

(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1.

(b)Both statements 1 and 2 are correct and statement 2 is not the correct explanation of statement1.

(c)Statement 1 is correct explanation of statement1.

(d)Both statements 1 and 2 are

incorrect.

Two examples in which the

nitrogenous wastes are excreted

from body in the form of uric acid

are

(a)birds and lizards

(b) insects and bony fishes

(c)mammals and mollusks

(d) frogs and cartilaginous fishes.

Match the two columns and select

the correct option.

Column-IColumn-II

A.Cerebrump. p. Controlsthe

pituitary

B. Cerebellum q. Controls vision

and hearing

C.Hypothalamus r. Controls the

rate of heart

beat

D. Midbrains. Seat of

intelligence

t. Maintains

body posture

(a)A = t; B = s; C = q; D = p

(b)A = s; B = t; C = q; D = p

(c)A = t; B = s; C = p; D = q

(d)A = s; B = t; C = p; D = q.

In one polynucleotide strand of a

DNA molecule the ratio of

A + T/G + C is 0.3.

What is the A + G/T + C ratio of the

entire DNA molecule?

(a)0.3(b) 0.6

Which of the following statements

are correct regarding Na+ – K+ pump?

(i)Need energy (ATP) to work

(ii)Expels 3 Na+ for every 2K+ ions

imported

(iii)Works against a concentration

gradient

(iv) Maintains resting potential

(a) (i) and (iv)(b) (ii) and (iii)

(c)(i) and (iii)(d)All of these

An amino acid without an

asymmetrical carbon atom is

(a)histidine

(b) glycine

(d) proline.

Enzymes are different from catalysts

(a) being proteinaceous

(b) being used in a reaction

(c)Functioning at a high temperature

(d) having a high rate of diffusion

Digestion of both starch and protein

iscarried out by

(a) gastric juice

(b) gastric lipase

(d) pancreatic juice

(d) ptyalin

Is carried in the blood

(a) As dissolved gas

(b)As bicarbonates

(d) All of these.

Which one of the following is a

sesamoid bone?

(a) Pelvis

(b) Patella

(d) Pectoral girdle.

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