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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. |
In the question number 62, the distance from the thrower to the point where the ball returns to the same level is |
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Answer» 58 m `R=(u^(2)sin2theta)/(g)=((30ms^(-1))^(2)(SIN60^(@)))/(10ms^(-2))~~78` |
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| 2. |
For a liquid-gas interface, the convex side has a high pressure than the concave side. Which is better, washing of cloth in cool soap water or warm soap water? why? |
| Answer» Solution :WARM SOAP water because its SURFACE TENSION is low. | |
| 4. |
A point source of light is placed at a distance of 2f from a converging lens of focal length f. The intensity on the other side of the lens is maximum at a distance |
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Answer» F |
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| 5. |
Assertion - Component of A along B is equal to component of b along A. ReasonCompoent of A along B is A cos theta ,Where theta is the angle between two vector . |
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Answer» If both Assetion and Reason are correct but Reason is the correct explanation of Assertion. |
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| 6. |
Which of the following combinations of three different physical quantities P, Q, R can never be a meaningful quantity? |
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Answer» `PQ-R` |
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| 7. |
If a person standing on a rotating disc stretches out his hands, the angular speed will |
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Answer» increase |
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| 8. |
Consider the x - axis as representing east, the y - axis as north and z - axis as vertically upwards. Give the vector representing each of the following points and the direction is of 45°. a) 5 m north east and 2 m up b)4 m south east and 3 m up c) 2 m north west and 4 m up |
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Answer» SOLUTION :`X = 2 cos 45^(@) = (2)/(sqrt(2)) HAT (i)` `Y = 2 sin 45^(@) = (2)/(sqrt(2)) hat (j)` `Z = 4m = 4 hat (k)` `:. (- hat(i) + hat(j)) sqrt(2) + 4 hat(k)` 
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| 9. |
The total energy at amplitude of 4 cm of a particle executes a SHM is 20 J. What will be its total energy at distance x = 2 cm? |
| Answer» Solution :TOTAL energy does not depend on displacement so total energy 20 J. | |
| 10. |
Assertion : The materials which have very small range of plastic extension are called brittle material. Reason: If the stress is increased beyond the elastic limit, thematerialwillbreak. |
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Answer» |
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| 11. |
A meteorite burns in air. Is the momentum of the meteorite conserved? |
| Answer» Solution :Momentum is conserved even when the meteorite BURNS in air. The meteorite loses some momentum which GETS TRANSFERRED to the surrounding air particles and to the gases that the meteorite is transformed into. The TOTAL momentum is conserved because there is no external FORCE. | |
| 12. |
Ideal monoatomic gas is taken through a process dQ = 2dU. What is the molar heat capacity for the process ? (where dQ is heat supplied and dU is change in internal energy) |
| Answer» SOLUTION :`C=(dQ)/(ndT) = (2dU)/(ndT) = (2nC_(V)dT)/(ndT) = 2C_(v)=3R` | |
| 13. |
(A) Am empty test tube dipped into water in a beaker appears, silver when viewed from a suitable direction. ( R) Due to refraction of light, the substance in water appears silvery. |
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Answer» Both A and R are TRUE and R is the correct explanation of A |
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| 14. |
The kinetic energy (K) and potential energy (V) of a particle performing a simple harmonic motion are such that, always |
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Answer» `KgtV` |
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| 15. |
Assertion :The processin whichheattransferisbyactualmovementof molecules influidssuchasliquids andgasesiscalledconduction . Reason :Newton'slaw of coolingstatesthatrateof lossof heatof a bodyis directlypropositionalto thedifferencein thetemperaturebetweenthatbodyand itssurrounding . i.e.(dtheta)/(dt ) prop^(-) (T-T_(s)) |
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| 16. |
A spring of force constant 'k' is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force constant of …………… |
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Answer» Solution :Ratio in which spring is cut = 1:2 Length of LARGER piece `=(2L)/3` FORCE constant `prop =1/("length of the spring")` `K/K. = (((2L)/3))/L = 2/3 , K. =3/2 K` |
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| 17. |
A bullet of mass 10 gm hits a fixed target and penetrates through 8 cm in it before coming to rest.If the average resistance offered by the target is 100 N, the velocity with which the bullet hits the target is, |
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Answer» 20 m/s |
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| 18. |
The time of oscillation of a small drop of liquid under surface tension depends upon density rho, radius r and surface tension s, as T alpha rho^(a) s^(b) r^(c ), then the descending order of a, b and c is |
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Answer» `a GT B gt C` |
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| 19. |
Four particles each of mass 1 kg are at the four corners of a square of side 1m. The M.I. of the system about a normal axis through centre of square is |
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Answer» `6" KGM"^(2)` |
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| 20. |
Which of the following is possible? |
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Answer»
 In CASE of insufficient length of capillary tube the SHAPE of meniscus is as below 
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| 21. |
The condition for rolling without slipping on a slope having friction is …... . |
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Answer» |
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| 22. |
The following graph respresent the pressure versus number density for ideal gas at two different temperature T_(1) and T_(2). The graph implies ................. . |
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Answer» `T_(1)=T_(2)` |
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| 23. |
The measured mass and volume of a body are 53.63 g and 5.8 cm^3respectively, with possible errors of 0.01 g and 0.1 cm^3 . The maximum percentage error in density is about |
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Answer» 0.002 |
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| 24. |
In the case of closed end organ pipe |
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Answer» the MAXIMUM possible WAVELENGTH is same as that of open end organ pipe |
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| 25. |
80 g of water at 30^@C is poured on a large block of ice at ^@C. The mass of ice that melts is |
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Answer» 30g |
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| 26. |
The condition under which the vector (a+b) and (a-b) are parallel is |
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Answer» `abot b` `(a+B)xx(a-b)=0 ` `therefore 2(AXXB)=0` |
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| 27. |
One end of a uniform rod of length 1 m is placed in boiling water whil its other end is placed in melting ice. A point P on the rod is maintained at a constant temperature of 800^@C . The mass of steam produced per second is equal to the mass of ice melted per second. If specific latent heat of steam is 7 times the specific latent heat of ice, then the distance of P from the steam chamber is n/18 m.Find the value of n? |
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| 28. |
When a body brought from infinity to r distance, its potential energy ...... "" (Fill in the blank) |
| Answer» SOLUTION :`IMPLIES`DECREASES or NEGATIVE. | |
| 29. |
A particle of mass m moving in the x direction with speed 2v is hit by another particle of mass 2m moving in the y direction speed v. If the collision is perfectly inelastic, the percentage loss in the energy during the collision is close to : |
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Answer» 0.44 |
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| 30. |
In the arrangement shown in figure, m_A=2kg and m_B=1kg. String is light and inextensible. Find the acceleration of centre of mass of both the blocks. Neglect friction everywhere. |
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Answer» Solution :NET pulling force on the system is `(m_(A) - m_(B))g` or `(2-1)g=g` TOTAL mass being pulled is `m_(A) + m_(B)` or 3 kg  `therefore a = ("Net pulling force")/("Total mass") =g/3`= acceleration of each block. Now, `veca_(CM) =(m_(A)veca_(A) + m_(B)veca_(B))/(m_(A) + m_(B)) =((2)(a) -(1)(a))/(1+2) =a/3 = g/9` downwards. |
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| 31. |
On end of a thin uniform rod of length L and mass M_(1) is rivetted to the centre of a uniform circular disc of radius .r. and mass M_(2) so that both are coplanar. The centre of mass of the combination from the centre of the disc is (Assume that the point of attachment is at the origin) |
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Answer» `(L(M_(1)+M_(2)))/(2M_(1))` |
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| 32. |
What happens to the time period of a simple pendulum kept inside a life, when the lift (i) moves up with acceleration 'a'? (ii) moves down with acceleration 'a'? |
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Answer» Solution :(i) When LIFT is moving up with ACCELERATION .a. then RELATIVE acceleration = g+a Time PERIOD `T = 2pi sqrt(l/(g+a))` so when lift is moving up with UNIFORM acceleration time period of pendulum in it decreases. (ii) When lift is moving down with acceleration .a. time period `T= 2pi sqrt(l/(g-a))` (g-a = relative acceleration of pendulum). Sotime period of pendulum in the lift increases. |
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| 33. |
Bernoulli's equation for steady, non-viscous, incompressible flow expresses the: |
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Answer» CONVERSATION of density |
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| 34. |
What is the angle between the equatorial plane and the orbital plane of (a) polar satellite ? (b) geostationary satellite ? |
Answer» Solution :`implies` Consider the diagram where PLANE of geostationary and POLAR satellite are SHOWN.  From figure, (a) `90^@` (B) `0^@` |
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| 35. |
A 2kg block is dropped from a height of 0.4 m on a spring of force constant 1960 Nm^(-1). The maximum compression of the spring is |
| Answer» ANSWER :A | |
| 36. |
"If the resultant internal force on system is zero, then its linear momentum remains constant". This is statement of law of conservation of linear momentum. |
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Answer» |
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| 37. |
The total energy of a particle executing SHM is |
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Answer» `ALPHAX` |
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| 38. |
Assertion : In a stationary sound wave, a displacement node is a pressure antinode and vice versa. Reason : Nodes and antinodes are the points of maximum displacement. |
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Answer» If both ASSERTION and REASON are CORRECT and reason is a correct EXPLANATION of the assertion. |
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| 39. |
A boy of mass M is applying a horizontal force to slide a box of mass M' on a rough horizontal surface. The coefficient of friction between the shoes of the boy andthe floor is mu and that between the box and thefloor is mu'. In which of the following case it is certainly not possible to slide the box? |
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Answer» `MU LT mu',MltM'` |
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| 40. |
The unit of length, metre was originally defined as the distance between two fine lines engraved on gold plugs near the ends of a bar of platinum-iridium alloy that is kept 0^@ C. Then the unit was defined in October 1983 in terms of wavelength of kr. 86 radiation . Now, the present unit is defined in terms of distance travelled by light . In your opinion, which of the two essential requirements for a standard unit availability, invariability played the key role in this modification. |
| Answer» SOLUTION :INVARIABILITY. | |
| 41. |
In a standing wave, node is a paint of |
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Answer» MAXIMUM STRAIN |
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| 42. |
A balloon of gross weight w newton is falling vertically downward with a constant acceleration a(lt g) .The magnitude of the air resistance is : |
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Answer» W |
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| 43. |
Explain how time was measured in ancient times. Also write note on cesium clock (atomic clock). |
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Answer» Solution :In ancient times from length of shadow of an object casted by sunlight time was estimated. Jantarmantar is located in Jaipur present also. Time is measured by pendulum clock also. Now we use atomic clock for standard time measurement. It is based on the periodic vibration produced in cesium atom. In the cesium atomic clock the second is taken as time needed for 9,192,631,770 vibration of the radiation corresponding to transition between the two hyperfine levels of the ground state of cesium-133 atom. The vibration of cesium atom regulate the rate of this cesium clock just as the vibration of a balance wheel regulate an ordinary wrist watch. The cesium atomic clock are very accurate. In principle they provide portable standard. By using 4 cesium clock national standard of time and frequency are maintained. For Indian Standard Time (IST) cesium atomic clock at NPL (National Physical Laboratory) at New Delhi is used. Uncertainty in time resolution is ` +-1 XX 10^(-13)` sec obtained. They LOSE or gain no more than `3mus` in one year. In view of tremendous ACCURACY in time measurement SI unit of length has been EXPRESSED in terms of path length light travels in certain interval of time. Distance TRAVELLED by light in `(1)/(2999792458)` second is called I meter. The time interval of events that we come across in the universe vary over a very wide range. Table 2.5 gives the range and order of some typical time intervals. 
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| 44. |
''Water pipes are painted with aluiminium paints''. Why? |
| Answer» Solution :PIPE PAINTED with aluminium paint is a bad radiator and so it EMITS less HEAT. | |
| 45. |
A body is dropped from a height H. Its kinetic energy will be equal to its potential energy at a height |
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Answer» `H/2` |
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| 46. |
(A) When a ball hits a wall (stationary) it returns back with same velocity, if collision is elastic.(B) A ball hits a bus moving towards it. If the collision is perfect inelastic, they move together.Inelastic collision arises due to loss in K.E during collision. |
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Answer» A, B are TRUE |
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| 47. |
A particle of mass m moving with velocity u collides elastically with a particle of mass 3m at rest. After collision the heavier particle moves with velocity |
| Answer» Answer :C | |
| 48. |
What is the phase difference between the displacement and acceleration of a particle executing SHM? |
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Answer» SOLUTION :`180^(@)" or "PI RAD` ACCELERATION `a propto - y`. |
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| 49. |
Match the items mentioned in the lists I and II belowLIST - I(a) Static friction(b) Limiting friction(c ) Kinetic friction(d) Rolling frictionLIST - II(e ) constant for a given pair of surfaces (f) Independent of area of contact(g) Self adjusting(h) Has the least magnitude for a given normal reaction |
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Answer» a-e, b-f, C-g, d-h |
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