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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. |
Atmospheric pressure is P_(0) and density of water at the sea level is rho_(0). If the bulk modulus of water is B, calculate the pressure deep inside the sea at a depth h below the surface. |
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| 2. |
A particle executes SHM of time period T. Find time by the particle to go from its mean position to half of the amplitude. |
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Answer» Solution :Consider the EQUATION of motion, X = `A sin wT ,` At t=0 , x=0 i.e. , at MEAN position The particle will be at x = `A/2` , at a time , where `A/2` = `A sin omega t = sin omega t = 1//2` , `sin omega t = sin pi//6` `omega t = pi/6 ` (or) `(2PI)/(T) t = (pi)/(6) `(or) `t= T/(12)` , Time taken `T/(12)` |
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| 3. |
Hotter liquids move faster than colder ones. Why? |
| Answer» Solution :VISCOSITY of LIQUID DECREASES with the increases of TEMPERATURE. | |
| 4. |
Three uniform spheres each of mass m and radius R are kept in such a way that each touches the orher two. Find the magnitude of the gravitational force on any one of the spheres due to the other two. |
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Answer» `(3Gm^2)/D^2` |
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| 5. |
Three bodies are lying on a frictionless horizontal table and these are connected as shown in the figure. They are pulled towards right with a force T_(3) = 60N If m_(1), m_(2)and m_(3), are equal to 10 kg, 20kg and 30kg respectively, then the values of T_(1) and T_(2) will be |
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Answer» `10N,10N` `T_(2)-T_(1)=m_(2)a, T_(1)=m_(1)a, a=(T_(3))/(m_(1)+m_(2)+m_(3))` |
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| 6. |
If pressure P, velocity V and Time T are taken as fundamental physical quantities the dimensional formula of the force is |
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Answer» SOLUTION :Let force `= F = P^(a)V^(b) T^(c )` `(F )= M^(1) L^(1) T^(-2), (P)= M^(1)L^(-1) T^(-2)` `(V)= M^(0)L^(1)T^(-1), (T)= M^(0)L^(0)T^(1)` `therefore MLT^(-2)= (ML^(-1)T^(-2))^(a) (M^(0)L^(1)T^(-1))^(b) (M^(0)L^(0)T^(1))^( c)` `MLT^(-2)= M^(a)L^(-a+b) T^(-2a-b +c)` `therefore` Comparing powers of M, L, T on both sides `a=1, -a+b=1 therefore b=2 and -2a- b+c = -2, -2 -2 =c = -2, c=2` `therefore` Force (F) `= PV^(2)T^(2)` |
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| 7. |
If error in measurement of a length of a cube is 3%, what is error in area of its one side ? |
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Answer» 0.03 |
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| 8. |
In s series of successive measurements in an experiment, the readings of the period of oscillation of a simple pendulum were found to be 2.63s,2.56s,2.42s,2.71s" and "2.80s. Calculate The percentage error. Express the results in proper form. |
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Answer» SOLUTION :`t_1= 2.63s, t_2=2.56s, t_3=2.42s, t_4= 2.71s, t_5= 2.80s` PERCENTAGE ERROR in `T= 0.04xx 100%= 4%`. |
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| 9. |
A hot liquid in beaker at 80^(@)C cools down to 70^(@)C in 2 minutes in an atmosphere of 30^(@)C temperature, then time taken to cool it down from 60^(@)C to 50^(@)C is . . . . . . .. |
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Answer» 240 Average temperature in SITUATION - 1 `T_(1)=(80+70)/(2)=75^(@)C` Average temperature in situation - 2 `T_(2)=(60+50)/(2)=55^(@)C` According to Newton.s COOLING rate, `(dT)/(dt)=K.(T-T_(s))` `:.(dT)/(K.)=(T-T_(s))dt` But `(dT)/(K.)` is constant `:.(T-T_(S))dt="constant"` `:.(T_(1)-T_(s))t_(1)=(T_(2)-T_(s))t_(2)` `:.t_(2)=((T_(1)-T_(s))/(T_(2)-T_(s)))t_(1)` `=((75-30)/(55-30))2xx60` `=(45)/(25)xx120` `:.t_(2)=216s` |
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| 10. |
A liquid flowing from a vertical pipe has a very definite shape as it flows from the pipe. To get the equation for this shapes assume that the liquid is falling under gravity once it leaves th pipe. Just as it leaves the pipe, the liquid has speed V_(0) and the radius of the stream of liquid is r_(0) Combining the above result with the equation of continuity the expression for the radius of the stream as a function of ..y..is |
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Answer» `R=(r_(0)SQRT(V_(0)))/((V_(0)^(2)+2gy)^(1//2))` |
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| 11. |
A liquid flowing from a vertical pipe has a very definite shape as it flows from the pipe. To get the equation for this shapes assume that the liquid is falling under gravity once it leaves th pipe. Just as it leaves the pipe, the liquid has speed V_(0) and the radius of the stream of liquid is r_(0) Speed (V)of the liquid as a function of the distance .y. it has fallen is given by |
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Answer» `V=sqrt(V_(0)^(2)+2gy)` |
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| 12. |
In s series of successive measurements in an experiment, the readings of the period of oscillation of a simple pendulum were found to be 2.63s,2.56s,2.42s,2.71s" and "2.80s. Calculate The mean absolute error in each measurement. |
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Answer» SOLUTION :`t_1= 2.63s, t_2=2.56s, t_3=2.42s, t_4= 2.71s, t_5= 2.80s` ABSOLUTE ERROR `triangleT =T_m -t` `triangleT_1= 2.62-2.63=0.01s` `TRIANGLE T_2= 2.62-2.56= +0.06s` `triangleT_3= 2.62-2.42= +0.20s` `triangleT_4=2.62-2.71= -0.09s` `triangleT_5= 2.62-2.80= -0.18s`. |
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| 13. |
Surface tension arises from the cohesive force between the surface molecules, Interplay between cohesion and adhension forces make the surface inclined at acute or obtuse angle with the contactingsolid surfaces. This causes a capillary rise (or fall) given as,h=(2T cos theta)/( rho g r)where theta= angle of contact, T = surface tension, rho=density of the liquid, g = acceleration due to gravity and r = radius of the capillary tube. In capillary rise |
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Answer» HEAT is evolved |
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| 14. |
In s series of successive measurements in an experiment, the readings of the period of oscillation of a simple pendulum were found to be 2.63s,2.56s,2.42s,2.71s" and "2.80s. Calculate The mean absolute error. |
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Answer» SOLUTION :`t_1= 2.63s, t_2=2.56s, t_3=2.42s, t_4= 2.71s, t_5= 2.80s` Mean absolute error `=(sum|triangleT_1|)/(n)` `triangleT_m= (0.01+0.06+0.20+0.09+0.18)/(5)` `TRIANGLE T_m = (0.54)/(5)=0.108s=0.11s` (Rounded off to `2^(ND)` decimal PLACE). |
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| 15. |
(A): Escape velocity from the surface of a black hole is greater than speed of light (R) : Light cannot escape from black hole |
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Answer» Both .A. and .R. are TRUE and .R. is the CORRECT EXPLANATION of .A. |
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| 16. |
Surface tension arises from the cohesive force between the surface molecules, Interplay between cohesion and adhension forces make the surface inclined at acute or obtuse angle with the contactingsolid surfaces. This causes a capillary rise (or fall) given as,h=(2T cos theta)/( rho g r)where theta= angle of contact, T = surface tension, rho=density of the liquid, g = acceleration due to gravity and r = radius of the capillary tube.In capillary action theta can be |
| Answer» Answer :D | |
| 17. |
Ship A is 10km due west of ship B. Ship A is heading directly north at a speed of 30kmph while ship B is heading in a direction 600 west of north at a speed 20kmph. Theirclosest distance of approach will be ……. |
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Answer» Solution :`bar(V_(A)) = 30jbar(V_(B))=20Sin60^(0)+20Cos60(hat(J))` `=-10sqrt3hat(i)+10hat(j)` `bar(V_(BA))=bar(V_(B))-bar(V_(A)) = -20hat(j)-10sqrt(3)hat(i)` If `phi` is the ANGLE MADE by `bar(V_(BA))` with X axis `Tanphi=(20)/(10sqrt(3))=(2)/(sqrt(3))` and `Sinphi=(2)/(sqrt(7))` From `DeltaABC, ("x")/(10)=(2)/(sqrt(7))` ` "x"=(20)/(sqrt(7))=7.56Km` 
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| 18. |
When a bus starts to move from rest, the passengers experience a sudden backward push is an example for |
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Answer» INERTIA of motion |
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| 19. |
A bucket fillled with water weighing 20 kg is raised from a well of depth 20m. If the linear density of the rope is 0.2 kg per meter, the amount of the work done is (g=10ms^(-2)) |
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Answer» 4000J |
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| 20. |
P-V diagram of an ideal gas for a process ABC is as shown in the figure. Plot pressure versus density graph of the gas for the process ABC. |
| Answer» SOLUTION :PRESSURE INCREASES to THREE TIMES | |
| 21. |
In s series of successive measurements in an experiment, the readings of the period of oscillation of a simple pendulum were found to be 2.63s,2.56s,2.42s,2.71s" and "2.80s. Calculate The relative error. |
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Answer» SOLUTION :`t_1= 2.63s, t_2=2.56s, t_3=2.42s, t_4= 2.71s, t_5= 2.80s` RELATIVE ERROR : `S_r = (triangleT_m)/(T_m)= (0.11)/(2.62)= 0.0419` `S_r= 0.04`. |
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| 22. |
Surface tension arises from the cohesive force between the surface molecules, Interplay between cohesion and adhension forces make the surface inclined at acute or obtuse angle with the contactingsolid surfaces. This causes a capillary rise (or fall) given as,h=(2T cos theta)/( rho g r)where theta= angle of contact, T = surface tension, rho=density of the liquid, g = acceleration due to gravity and r = radius of the capillary tube.If the vessel accelerates up, capillary rise |
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Answer» INCREASES |
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| 23. |
A cylinder of height 20m is completely filled with water. The velocity of efflux of water (in "ms"^(-1) ) through a small hole on the side wall of the cylinder near its bottom is |
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Answer» `10 "MS"^(-1)` |
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| 24. |
Consider a heat engine as shown in Fig. Q_(1)and Q_(2)are heat added to heat bath T_(1)and heat taken from T_(2)in one cycle of engine. W is the mechanical work done on the engine If Wgt 0, then possibilities are : a) Q_(1) gt Q_(2) gt 0 b) Q_(2) gt Q_(1) gt 0 c) Q_(2) gt Q_(1) lt 0 d) Q_(1) lt 0, Q_(2) gt 0 |
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Answer» only a,B are correct |
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| 25. |
A planet is revolving round the sun. Its distance from the sun at apogee is r_Aand that at perigee is r_p . The masses of plancet and sun are .m. and M respectively, v_Ais the velocity of planet at apogee and v_pis at perigee respectively and T is the time period of revolution of planet round the sun, then identify the wrong answer. |
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Answer» `T^(2)=(pi^2)/(2GM)(r_A+r_P)^3` |
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| 26. |
A body of mass 25 kg is at rest on a horizontal surface. Minimum horizontal force required to just start the motion is 73.5 N and a force of 49 N is needed to keep the body moving with a constant velocity. What is the coefficient of static friction? |
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Answer» `0.2` |
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| 27. |
A force F acting on a body depends on its displacement s as F alpha s^(-1//3).The power delivered by F will depend on displacement as |
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Answer» `s^(2//3)` |
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| 28. |
Transverse wave of the same frequency are generated in two steel wires A and B.Diameter of A is twice that of B and tension is A is half that of B.The ratio of velocities of waves in A and B is |
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Answer» `1:2` |
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| 29. |
A body is thrown vertically upward from a point .A. 125 m above the ground. It goes up to a maximum height of 250 m above the ground and passes through .A. on its down- ward journey. The velocity of the body when it is at a height of 70 m above the ground is (g= 10ms^(-2)) |
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Answer» `50ms^(-1)` |
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| 30. |
A ball is dropped from the top of a building. It takes 0.5s to fall past the 3m length of a window some distance from the top of the building. If the velocity of the ball at the top and the bottom of the window are V_(T) and V_(8) respectively then V_(T)+V_(B)=? |
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Answer» SOLUTION :`S=((u+V)/(2))t` `3=(v_(T)+v_(B)/(2))0.5`  `V_(T)+V_(b)=12m//s`
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| 31. |
The properties of a surface are different from those of the bulk liquid because the surfce molecules are |
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Answer» are smaller than other MOLECULES |
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| 32. |
A lift is moving down with an acceleration equal to the acceleration due to gravity. A body of mass M kept on the floor of the lift is pulled horizontally. If the coefficient of friction is, then the frictional resistance offered by the body is |
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Answer» `mu_(k)Mg` |
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| 33. |
Which of the following uses vernier scale |
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Answer» Meter SCALE |
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| 34. |
A certain amount of monoatomic gas undergoes a process for which U^beta alpha V ,where U is internalenergy and V is volume of gas. It is found that the ratio (Delta U)/(Delta Q)for the process is 1/3 . What is the valueof beta? |
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| 35. |
A body starts from rest and travel distance S with uniform acceleration, then moves uniformly a distance 2S and finally comes to rest after moving further 5S under uniform retardation. Find the ratio of average velocity to maximum velocity: |
Answer» Solution :Graphically : Area of (V-t) curve represent displacement  `S=1/2 V_("max") t_(1) or t_(1)=(2S)/(V_("max"))`, `2S=V_("max") t_(2) ot t_(2)=(2S)/(V_("max"))` `5S=1/2 V_("max") t_(3) or t_(3)=(10S)/(V_("max"))` `V_(av)=("Total displacement")/("Total time") , V_(av)=(S+2S+5S)/((2S)/(V_("max"))+(2S)/(V_("max"))+(10S)/(V_("max")))` `V_(av)/V_("max")=(8S)/(14S)=4/7 (OR)` `(V_(av))/V_("max")=("Total displacement")/(2("total displacement during acceleration andretardaton")+("Displacement During uniform velocity"))` `V_(av)/(V_("max"))=(8S)/(2(S+5S)+2S)=(8)/(14)=(4)/7` |
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| 36. |
If the Poission.s ratio of a solid is 2/5. Find the ratio of its Young.s modulus to the rigidity modulus |
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Answer» `5//4` |
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| 37. |
The measured mass and volume of a body are 2.42 g and 4.7 cm^3 respectively with possible errors 0.01 g and 0.1 cm^3. Find the maximum error in density. |
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| 38. |
An artifical satellite of a planet revolves in a circular orbit whose radius exceeds the radius of the planet 7 times. IN the process of motion, the satellite experiences slight resistance due to cosmic dust. Assuming the resistive force depends on the speed of the satellite as F = kv^(2) (where k is a constant). The time by the satellite will stay in orbit until it falls on to the planet.s surface. is (m)/(ksqrt(gR)) (sqrt(x)-1) (Given m = mass of the satellite, g = accleration due to gravity at the surface of planetand R = radius of the planet ). FInd the value of x |
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| 39. |
Assertion - If |A|=|B|,then (A+ B) , (A-B ) and (AxxB) aaraea three mutually perpendicular vectors . Reason - Dot Produt od a null vector with any other vector is always zero . |
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Answer» If both Assetion and Reason are correct but Reason is the correct EXPLANATION of Assertion. this dot PRODUCT is zero only if A=B . Therefore they are PERPENDICULAR .Further `,(AxxB)` isperpendicular to both `(a+B) and (a-B)`. |
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| 40. |
Statements :(a) Ration of the distance of the centre of mass of a two particle system are in the inverse ratio of their masses : (b) The location of the centre of mass is independent of the reference frame used locate it |
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Answer» Only a is TRUE |
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| 41. |
In the following question which one of the statements is correct? Head on collision signifies collision with: |
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Answer» VELOCITIES of equal magnitudes |
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| 42. |
A thin circular metal disc of radius 500 mm is set rotating about a central axis normal to its plane. Upon rising the temperature gradually, the radius increases to 507.5 mm. Find the percentage change in the rotational kinetic energy of the disc? |
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| 43. |
Graph between the applied force and the change in length of a wire within elastic limit is a |
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Answer» STRAIGHT LINE with negative slope |
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| 44. |
One of the most efficient engines ever developed operates between 2100 K and 700 K. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this? |
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Answer» Solution :`T_(1) = 2100K, T_(2)= 700 K` The maximum possible efficiency `= eta = (T_(1) - T_(2))/( T_(1)) ` `= (2100 - 700)/(2100) = 0.667` `= 66.7%` ACTUAL efficiency `= 40%` `("Actual efficiency")/(" Maximum efficiency") = ( 40 xx 100)/(100 xx 66. 67) = 60%` |
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| 45. |
A raw egg and hard boiled egg are made to spin on a table with the same angular speed about the same axis. The ratio of the time taken by the eggs to stop is |
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Answer» `=1` `:.` ..I.. will increase in turn it decreases `OMEGA`. THEREFORE it takes lesser TIME than boiled egg `("time for raw egg")/("time for boiled egg") lt1` |
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| 46. |
A uniform metre scale of mass 2kg is suspended from on end. If it is displaced through an angle 60^(@) from the vertical, the increases in its potential energy is , |
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Answer» 4.9 J |
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| 47. |
A ball moving with a velocity of 6 m/s strikes an identical stationary ball. After collision each ball moves at angle of 30^@ with the original line of motion. Assuming that the collision is elastic, what are the speeds of the balls after the collision? |
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Answer» `(SQRT3)/2 m//s, 2sqrt(3) m//s`  According to the law of conservation of momentum along vertical and horizontal directions, we get `0 = mv_1 sin 30^@ - m v_2 sin 30^@ ` or `v_1 = v_2 "" …..(i)` `m xx u + m xx 0 = mv_1 cos 30^@ + mv_2 cos 30^@ "" .......(ii)` Putting EQN. (i) in eqn. (ii), we get , `m u = 2 mv_1 cos 30^@` or `m xx 6 = 2 xx m xx v_1 xx (sqrt3)/(2) "or " v_1= (6)/(sqrt3) = 2sqrt(3) m//s` From (i), we get, `v_1 = 2sqrt(3) m//s`. |
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| 48. |
A load of mass .M. is attached to the bottom of a spring of mass .M/3. and spring constant .K.. If the system is set into oscillation, the time period of oscillation is |
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Answer» `(2PI)/3 SQRT((10 M)/K)` |
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| 49. |
A block of mass 3 kg is at rest on a rough inclined plane with angle of inclination 30^@with horizontal. If mu_s= 0.7, then the frictional force is |
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Answer» 17.82 N |
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| 50. |
The restoring force which brings the bob toward the mean position is equal to |
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Answer» Weight of BOB |
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