Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

(A): It is possible to transfer heat energy from body at lower temperature to body at higher temperature by using external agency (R ): External agency extracts more heat from colder body by doing work rejects less heat to hotter body, hence heat transfer is possible.

Answer»

Both (A) and(R ) are TRUE and (R ) is the correct EXPLANATION of (A)
Both (A) and (R ) are (R ) true and is not the correct explanation of (A)
(A) is true but (R ) is false
Both (A) and (R ) are false

Answer :C
Discussion
2.

Arrive at the expression for kinetic energy of particle executing SHM.

Answer»

Solution :`"K.E. of particle "=(1)/(2)m OMEGA^(2)A^(2)-(1)/(2)m omega^(2)X^(2)`
`=(1)/(2)m omega^(2)(A^(2)-x^(2))`
`"where"x=Acos (omegat+phi)`
`"AlsoK.E."=(1)/(2)MOMEGA^(2)(A^(2))(1-cos^(2)(omegat+phi))`
`"i.e.,K.E"=(1)/(2)m omega^(2)A^(2)SIN^(2)(omegat+phi)`
Discussion
3.

Two forces are such that the sum of their magnitudes is 18 N, the resultant is sqrt(228) when they are at 120^(@). Then the magnitude of the forces are

Answer»

12N, 6N
13N, 5N
10N, 9N
16N, 2N

Answer :D
Discussion
4.

A train is moving with a speed of 20 m/s at a place where the radius of curvature of the railway line is 1500 m. Calculate the distance between the rails if the elevation of the outer rail above the inner rail is 0.042 m ?

Answer»


Solution :`l = rhg//v^(2) = 1500 XX 0.042 xx 9.8 -20^(2) = 1.54 m`
Discussion
5.

A uniform cube of side a and mass m rests on a rough horizontal table. A horizontal face F is applied normal to one of the face at a point directly above the centre of the face, at a height (3a)/(4) above the base. What is the minimum value of F for which the cube begins to topple about an edge ?

Answer»

Solution :In the limiting ESE normal REACTION will PASS through O. The cube will topple about O if torque of F ecceeds the torque of mg.
`impliesF((3a)/(4)) GT mg ((a)/(2))`
`impliesF gt (2)/(3)mg`
So, the minimum value of `F` is `(2)/(3)mg`
Discussion
6.

Fig. (1) shows the graphs of elongation versus temperature for two different metals. If these metals be employed to form a straight bimetallic strip of thickness 6cm and heated it bends in the form ofan arc, the radius of curvature changing with temperature approximately as shown in fig(2). The linear expansivities of the two metals are

Answer»

`24 xx 10^(-6) //°C and 12 xx 10^(-6)//°C`
`20 xx 10^(-6)//°C and 10 xx 10^(-6)//°C`
`18 xx 10^(-6)//°C and 10^(-6)//°C`
`16 xx 10^(-6)//°C and 8 xx 10^(-6)//°C`

Answer :D
Discussion
7.

In the previous question, if R is the radius of the planet and g is the acceleration due to gravity at its surface then the body will reach the centre of the planet in time

Answer»

`2PI SQRT(R//g)`
`PI sqrt(R//g)`
`pi/2sqrt(R//g)`
`sqrt(2R//g)`

ANSWER :C
Discussion
8.

The side of a cube, as measured with a vernier calipers of least count 0.01 cm is 3.00 cm. The maximum possible error in the measurement of volume is

Answer»

`PM 0.01 "CM"^(3)`
`pm 0.06 "cm"^(3)`
`pm 0.0 "cm"^(3)`
`pm 0.27 "cm"^(3)`

ANSWER :D
Discussion
9.

A monoatomic ideal gas of two moles is taken through a cyclic process starting from A as shown figure. The volume rations are (V_(B))/(V_(A))=2 and (V_(D))/(V_(A))=4 If the temperature fT_(A)at A is 27^(@)C. Calculate,

Answer»

the TEMPERATURE of the gas at point B,
heat absorbed or relaesed FBY the gas in each process,
the total WORK done by the gas during the COMPLETE cycle
Express your answer in terms of the gas constant R

Answer :(a)600K (b) 1500r,831.8r,-900R,-831.8r(c)600r
Discussion
10.

A body moves over a plane surface , starting from rest. The frictional force is constant. The attractive foce is (P-Kt) in gravitational units. The maximum velocity is attained after t seconds . What is the distance coverd before it attains the maxomum speed if the mass of body is m

Answer»


ANSWER :`(GKT^(3))/(3M)`
Discussion
11.

A cylinder rolls without slipping down an inclined plane, the number of degrees of freedom it has, is

Answer»

2
3
5
1

Answer :A
Discussion
12.

If the masses and mutual distance between the two objects are doubled, what is the change in the gravitational force between them?

Answer»

Solution :ByNewton.slaw of gravitaional
` F = (GM_(1)M_(2))/(r^(2))`
Here , the massesand mutual DISTANCEBETWEEN the TWO objectsare DOUBLED
` F = (G(M_(1))(2M_(2)))/((2r)^(2)) = (4GM_(1)M_(2))/(4r^(2))`
` F = (GM_(1)M_(2))/(r^(2))`
Thereis no changein the GRAVITATIONAL forcebetweenthem .
Discussion
13.

Find the final velocities of the masses after in collision the given situations.

Answer»


Answer :(i) `v_(1)=0,v_(2)=3` (Rightwards)
(ii) `v_(1)=.3` (Rightwards), `v_(2)1.8`(Rightwards)
(iii) `v_(1)=2.1` (Rightwards),`v_(2)=2.6`(Rightwards)
(IV) `v_(1)=1.8`(LEFTWARDS), `v_(2)=1.2`(Rightwards)
(v) `v_(2)`(leftwards),`v_(1)`(Rightwards)
Discussion
14.

If F=2i+3j-k and r=i-j+6k find rxxF

Answer»

`-17i+13j+5k`
`-17i-13j-5k`
`3i+4j-5k`
`-3i-4j+5k`

ANSWER :A
Discussion
15.

Two rods of equal length are lying one along x-axis and the other along line y =x they intersect at origin at their midpoint. The first rod moves with velocity V_(1) = v hat(j) and second one with velocity (V)/(sqrt(2)) hat(i) - (V)/(sqrt(2))hat(j). The velocity of point of intersection of rods is 2.41 hat(i) + p hat(j). The value of 'p' is

Answer»


ANSWER :1
Discussion
16.

The escape velocity of a projectile from the earth.s surface is given by the formula (R toradius of the earth and .g. is acceleration due to gravity)

Answer»

`SQRT(2gR)`
`sqrt(GR)`
`sqrt(g/R)`
`sqrt((gR)/2)`

ANSWER :A
Discussion
17.

In a refrigerator one removes heat from a lower temperature and deposits to the surroundings at a higher temperature. In this process, mechanical work has to be done, which is provided by an electric motor. If the motor is of 1kW pwer, and heat is transferred from -3^(@)C" to "27^(@)C , find the heat taken out of the refrigerator per second assuming its efficiency is 50%of a perfect engine.

Answer»

Solution :`eta=1-270/300=1/10`
EFFICIENCY of REFRIGERATOR=`0.5eta=1/20`
If Q is the HEAT/s transferred at higher TEMPERATURE then `W/Q = 1/20 or Q = 20W=20kJ` . And heat REMOVED from lower temperature=`(Q-W)=(20K-1K)=19kj`.
Discussion
18.

A body P is thrown vertically up with velocity 30 ms^(-1)and another body Q is thrown up along the same vertically line with the same velocity but 1 second later from the ground. When they meet

Answer»

<P>P TRAVELS for 2.5 s
Q travels for 3.5 s
P travels for 3.5 s
Q travels for 1 s

Answer :C
Discussion
19.

The motion of planet in the solar system is an example of the conservation of ...........

Answer»

mass
LINEARMOMENTUM
angular MOMENTUM
ENERGY

SOLUTION :`implies` Because the orbitial velocity of PLANETS depend on the law of conservation of momentum.
Discussion
20.

A freely falling body takes 2 seconds to reach the ground on a planet, when it is dropped from a height of 8m. If the period of a simple pendulum is pi seconds on the planet, the length of the pendulum is (cm).

Answer»

100
50
25
200

Answer :A
Discussion
21.

Springs of spring constants K,2K,4K,8K……20488K are connected in series. A mass m is attached to one end the system is allowed to oscillation. The time period is approximately

Answer»

`2pisqrt(m/(2K))`
`2pisqrt((2m)/K)`
`2pisqrt(m/(4K))`
`2pisqrt((4M)/K)`

Answer :B
Discussion
22.

A particle traversed along a straight line for first half time with velocity V_0. For the remaining part, half of the distance is traversed with velocity V_1 , and other half distance with velocity V_2 . Find the mean velocity of the particle for the total journey.

Answer»

`(2v_0(v_1+v_2))/(v_1+v_2 + 2v_0)`
`(v_0(v_1+v_2)+2v_1v_2)/(2(v_1+v_2))`
`(v_1+v_2)/(2)`
`(v_0+2v_1v_2)/(2(v_1+v_2))`

ANSWER :B
Discussion
23.

A wheelin uniformmotionabout an axispassingthrough its centreandperpendicularplusisconsideredto bein mechanical(translational plus rotational) equilibriumbecause no netexternalforceortorqure is reqiredtosustainits motionHowever, theparticlesthanconstitute thewheel doexperiencea centripetealtheaccelerationwheel beingin equilibrium ? howwouldyou seta halfwheelinto unifrom motionaboutanaxispassing throghthe centreof massof thewheelandperpendicularto itsplane? will ypurequire external forcestosustainthemotion ?

Answer»

Solution : Wheelis a rigid BODY, theparticlesthatconsiture the wheel doexperiencea centripetal accelerationdirected towards thecentre , this acceleration ARISES dueto INTERNAL eleasticforces , whichcancel out in pairs.
In a HALFWHEEL thedistributionof mass aboutits centreof mass(through whichaxis ofrotation passes ) is notsymmetrical , therefore , thedirectionof angular momentumof thewheeldoesnotcoincide withthedirectionof its angularvelocityHencean external TORQUE is required to maintainthe motionof thehalf wheel.
Discussion
24.

An ideal gas at 13^(@)C, is heated to double its volume at constant pressure. Find the final temperature of the gas.

Answer»

Solution :Initial temperature `t_(1)=13^(@)C,T_(1)=13+273=286K,` Initial VOLUME `V_(1)=V`
Final volume `V_(2)=2V` , Final temperature `t_(2)=?`
From Charles. law at constant pressure `rArr V_(1)/T_(1)=V_(2)/T_(2) rArr T_(2)=V_(2)/V_(1)T_(1)=(2V)/V times 286=572K`
Final temperature, `t_(2)=572-273=299^(@)C`
Discussion
25.

A Black metal foil receives radiation of power P from a hot sphere at absolute temperature T, kept at a distance d. lf the temperature is doubled and distance is halved, then Power will be

Answer»

<P>64P
16 P
4P
8P

Answer :A
Discussion
26.

Statements : (a) Ratio of the distances of the centre of mass of a two particle system are in the inverse ratio of their masses : br> (b) The location of the centre of mass is independent of the reference frame used locate it

Answer»

Only a is TRUE
Only B is true
Both a and b are true
Both a and b are false

Answer :C
Discussion
27.

Assertion : An ice ball is floating in water. Some stone pieces are embedded inside the ice. When ice will melt, level of water will fall. Reason : In floating condition, stone pieces will displace more liquid compared to the condition when they sink.

Answer»

If both Assertion and Reason are CORRECT and Reason is the correct EXPLANATION of Assertion.
If both Assertion and Reason are TRUE but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If Assertion is false but Reason is true.

Solution :Water level rises as stone PIECES displaces more liquid compared to condition when they sinks.
Discussion
28.

A cubic vessel (with faces horizontal + vertical) contains an ideal gas at NTP. The vessel is being carried by a rocket which is moving at a speed of 500 ms^(-1) in vertical direction. The pressure of the gas inside the vessel as observed by us on the ground

Answer»

Remains the same because `500ms^(-1)` is very much smaller than `upsilon_(RMS)` of the gas.
remains the same because motion of the vessel as a WHOLE does not affect the relative motion of the gas molecules and the walls.
will increase by a factor equal to `[upsilon)(rms)^(2) + (500)^(2)[//upsilon_(rms)^(2)` where `upsilon_(rms)` was the original nean SQUARE velocity of the gas.
will be different on the top wall and bottom wall of the vessel.

SOLUTION :The pressure of the gas inside the vessel, as OBSERVED by us, on the ground remains the same. This is because motion of the vessel as a whole does not affect the relative motion of gas molecules and the walls of the vessel.
Discussion
29.

Two narrow bores of diameters 3.00mm and 6.0mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? Surface tension of water at the temperature of the experiment is 7.3 times 10^-2 N m^-1.Take the angle of contact to be zero and density to water to be 1.0 times 10^3 kg m^-3

Answer»

Solution :For the first bore, PRESSURE difference (between the concave and convex side)=`2 times 7.3 times 10^-3/3 times 10^-3=48.7 Pa` Similarly for the second base, pressure difference =97.3 Pa Consequently the level difference in the TWO bores is `(48.7//(10^3 times 9.8)) m=5.0mm`
the level in the narrower bore is HIGHER.(Note for zero angle of CONTRACT,the radius of the meniscus equals of the bore. The concave side of the surface in each bore is at 1atm)
Discussion
30.

Is the apparent expansion coefficient of a liquid a constant?

Answer»

Solution :The apparent EXPANSION coefficient of a LIQUID is not a constant, it depends on the material of the CONTAINER in which the liquid is kept.
Discussion
31.

A body is pushed up on a rough inclined plane making an angle 30^(@) to the horizontal. If its time of ascent on the plane is half the time of its descent. Find coefficient of friction between the body and the inclined plane.

Answer»

SOLUTION :`sqrt3/5`
Discussion
32.

Let I_(1) and I_(2) be the moments of inertia of two bodies of identical geometrical shape, the first made of aluminimum and the second of iron.

Answer»

`I_(1) lt I_(2)`
`I_(1)=I_(2)`
`I_(1) GT I_(2)`
relatioan between `I_(1)` and `I_(2)` DEPENDS on the ACTUAL shapes of the bodies

Answer :A
Discussion
33.

A rectangular plank of mass .m_(1).and height .a. is on a horizontal surface. On the top of it another rectangular plank of mass .m_2. and height .b. is placed. The potential energy of the system is,

Answer»

`(m_(1) + m_(2))(a+b)/2 G`
`[(m_(1) + m_(2))/2. a + m_(2) b/2]g`
`[(m_(1)/2 + m_(2)) a + m_(2) b/2]g`
`[(m_(1)/2 + m_(2))a + m_(1)b/2]g`

ANSWER :C
Discussion
34.

A bodyof mass .m. dropped from a height .h. reaches the ground with a velocity sqrt((gh)/(2)). The work done by air resistance is

Answer»

`(MGH)/(2)`
`(mgh)/(4)`
`(2mgh)/(4)`
`(3mgh)/(4)`

ANSWER :D
Discussion
35.

When two sound sources of the same amplitude but of slightly different frequencies v_(1) and v_(2) are sounded simultaneously, the sound one hears has a frequency equal to

Answer»

`ABS(upsilon_(1)-upsilon_(2))`
`abs((upsilon_(1)-upsilon_(2))/2)`
`sqrt(upsilon_(1)upsilon_(2))`
`abs(upsilon_(1)+upsilon_(2))`

Solution :The resulting sound wave has a frequency EQUAL to half the sum of the individual frequencies. NOTE that the resulting intensity varies at the beat frequency equal to difference of the individual frequencies.
Discussion
36.

(1)/(2) mole of Helium gas is contained in a container at S.T.P. The heat energy needed to double the pressure of the gas, keeping the volume constant (heat capacity of the gas =3J g^(-1)K^(-1))

Answer»

3276 J
1638 J
819 J
409.5 J

ANSWER :B
Discussion
37.

A body of mass m, moving with a uniform velocity of 30 m s^(-1) collides with another body of mass m2 at rest and then the two together begin to move with a uniform velocity of 20 m s^(-1). The ratio of their masses ((m_1)/(m_2)) is

Answer»

0.75 
0.25 
4 
2 

ANSWER :D
Discussion
38.

A particle of mass m is thrown upwards from the surface of the earth, with a vilocity U. The mass and the radius of the earth are respectively, M and G is gravitational constant and g is acceleration due to gravity on the surface of the earth. The minimum value of U so that the particle does not return back to earth, is........

Answer»

`sqrt((2GM)/R)`
`sqrt((2GM)/R^2)`
`sqrt(2gR^2)`
`sqrt((GM)/R)`

Solution :`implies` Here U BECOMES a ESCAPE velocity
i.e. u`= sqrt (2gR) ` but `g = (GM)/R^2`
`:. U = sqrt(2(GM)/R^2.R)`
`= sqrt((2GM)/R)`
Discussion
39.

Passage - II : A small spherical monoatomic ideal gas bubble ( gamma- (5)/( 3) ) is trapped inside a liquid of density rho_1 [ see figure]. Assume that the bubble does not exchange any heat with the liquid. The bubble contains n moles of gas. The temperature of the gas when the bubble is at the bottom is T_0. the height of the liquid is H and the atmospheric pressure is rho_0 ( Neglect surface tension) The buoyancy force acting on the gas bubble is :

Answer»

`rho_(1) nRgT_(0) ((p_(0) + rho_(1) gH)^(2//5) )/( (p_(0) + rho_(1) gH)^(2//5) )`
`(p_(1) nRg T_0)/( (p_(0) + rho_(1) gH)^(2//5) [p_(0) + rho_(1) G(H-y) ] ^(3//5) `
`rho_(1) N R g T_(0) ((p_(0) + rho_(1) gH)^(3//5) )/( (p_(0)+ rho_(1) gy)^(8//5) )`
`(rho_(1) n Rg T_0)/( (p_(0) + rho_(1) g H)^(3//5) [p_(0) + rho_(1) g(H -y) ]^(2//5))`

Answer :B
Discussion
40.

Passage - II : A small spherical monoatomic ideal gas bubble ( gamma- (5)/( 3) ) is trapped inside a liquid of density rho_1 [ see figure]. Assume that the bubble does not exchange any heat with the liquid. The bubble contains n moles of gas. The temperature of the gas when the bubble is at the bottom is T_0. the height of the liquid is H and the atmospheric pressure is rho_0 ( Neglect surface tension) As the bubble moves upwards, besides the buoyancy force the following forces are acting on it.

Answer»

Only the FORCE of gravity
The force DUE to gravity and the force due to the PRESSURE of the liquid
The force due to gravity, the force due to the pressure of the liquid and the force due to viscosity of the liquid
The force due to gravity and the force due to viscosity of the liquid

Answer :D
Discussion
41.

Passage - II : A small spherical monoatomic ideal gas bubble ( gamma- (5)/( 3) ) is trapped inside a liquid of density rho_1 [ see figure]. Assume that the bubble does not exchange any heat with the liquid. The bubble contains n moles of gas. The temperature of the gas when the bubble is at the bottom is T_0. the height of the liquid is H and the atmospheric pressure is rho_0 ( Neglect surface tension) When the gas bubble is at a height y from the bottom, its temperature is :

Answer»

<P>`T_(0) ( (p_0 + rho_(1) GH)/( p_(0) +rho_(1) gy) )^(2//5)`
`T_(0) ((p_(0) + rho_(1) g(H-y) )/( p_(0) + rho_(1) gH) )^(2//5)`
`T_0 ((p_(0) + rho_(1) gH)/( p_(0) +rho_(1) gH) )^(3//5)`
`T_0 ((p_(0) + rho_(1)g(H-y) )/( p_(0) +rho_(1) gH) )^(3//5)`

ANSWER :B
Discussion
42.

In column - I report values of some physical quantities (or) calculations are mentioned and column - II, the number of significant figures are mentioned. Match column - I values appropriately to those mentioned in column - II{:(,"Column - I",,"Column - II"),((A),(3.20+4.80)xx10^(5),(P),4),((B),0.030,(Q),2),((C ),(3.8xx10^(-6))+(4.2xx10^(-5)),(R ),3),((D),3.033,(S),2):}

Answer»


ANSWER :A-R; B-Q; C-Q; D-P
Discussion
43.

An ideal gas at a pressure of 1 atm and temperature of 27^(@)C is compressed adiabatically until its pressure becomes 8 times the initial pressure , then final temperature is (gamma=(3)/(2))

Answer»

`627^(@)C`
`527^(@)C`
`427^(@)C`
`327^(@)C`

ANSWER :D
Discussion
44.

An ice cube of mass M and side of length a each is sliding friction across a counter top with a speed V_(0) when it hits a ridge O at the edge of the counter (see figure). This collision causes the cube to tilt as shown. The minimum value of V_(0) needed for the cube to fall of the table is given by V_(0)=sqrt((x+0.1)"ag") where 'x' is

Answer»


ANSWER :1
Discussion
45.

Which of the following is the most significant law of motion given by Newton?

Answer»

FIRST LAW of MOTION
Second law of motion
Third law of motion
ZEROTH law of motion

Answer :B
Discussion
46.

One of the two clocks on earth is controlled by a pendulum and other by a spring. If both the clocks be taken to the moon, then which clock will show same time as that on earth

Answer»

SPRING clock
pendulum clock
both '1' and '2'
neither '1' and '2'

Answer :A
Discussion
47.

The diameter of a rotating fly wheel is R. Its coefficient of linear expansion is alpha. If the temperature is increased by DeltaT, the percentage change in its rotational KE would be

Answer»

`alpha.Delta.100`
`2.alpha.Deltatxx100`
`(alphaDeltat)/(2)XX100`
`(2alphaDeltat)/(5)xx100`

ANSWER :B
Discussion
48.

A body is projected with velocity 24 ms^(-1) making an angle 30° with the horizontal. The angle made by the direction of the projectile with the horizontal at 2s from start is

Answer»

`TAN^(-1)""(2)/(3sqrt(3))`
`tan^(-1)""(1)/(3sqrt(3))`
`tan^(-1)""(2)/(3)`
`tan^(-1)""(1)/(3)`

ANSWER :A
Discussion
49.

The end B of the rod AB which makes angle theta with the floor is being pulled with a constant velocity v_(0) as shown. The length of the rod is l. At the instant when theta=37^(0)

Answer»

velocity of end A is `4/3v_(0)` downwards
angular velocity of ROD is `5/3(v_(0))/(L)`
angular velocity of rod is constant
VELOSITY of end A is constant

Answer :A::B
Discussion
50.

A long metallic bar is carrying heat from one of its ends to the other end under steady-state. The varitatin of temperature theta along the length x of the bar from its hot end is best described by which of the following graphs :

Answer»




ANSWER :B
Discussion