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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 14601. |
Take the efefct of bulging of earth and its rotation in account. Consider the following statements. (A) There are points outside the earth where the value of g is equal to its value at the equator (B) There are points outside the earth where the value of g is equal to its value at the poles |
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Answer» Both A and B are CORRECT |
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| 14602. |
. . . . . . gives relation between temperature and colour of star. |
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Answer» WEIN's displacement LAW |
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| 14603. |
What is the relation connecting linear displacement and angular displacement ? |
| Answer» SOLUTION :Linear DISPLACEMENT `VEC(Deltas) = vec(Deltatheta) XX vecr` | |
| 14604. |
20g of steam at 100^(@)C is passed into 100g of ice at 0^(0)C. Find the resultant temperature if specific latent heat of steam is 540 callg., specific latent heat of ice is 80 cal/g and specific heat of water is 1 cal/g^(0) C . |
| Answer» Answer :D | |
| 14605. |
Figure shows two rays A and B being reflected by a mirror and going as A and B. The mirror |
| Answer» Answer :A | |
| 14606. |
A person walking at 4 m/s finds rain drops falling slant wise in to his face with a speed of 4m/s at an angle of 30^(@) with the vertical th actual speed of the rain drops is ______ |
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Answer» 4m/s |
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| 14607. |
A load W is to be raised by a rope from rest to rest through a height h The greatest tension the rope can safely bear is nW. The least time in which the ascent can be made will be: |
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Answer» `[(2H)/((n-1)G)]^(1//2)` |
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| 14608. |
Passage - I : When the force F is applied the body may topple about A or it may translate. If the block is a cube of edge a and mu=0.6 then |
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Answer» the body will TRANSLATE |
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| 14609. |
20 g of steam at 100^(0)C is passed into 100g of ice at 0^(0)С. Find the resultant temperature if specific latent hear of steam is 540 cal/g, specific latent heat of ice is 80 cal/g and specific heat of water is 1 "cal/g"^(0)C. |
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| 14610. |
Consider the following two equations (A) L=I omega(B)(dL)/(dt)=tau In noninertial frames |
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Answer» both A and B are TRUE |
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| 14611. |
The correctness of equation can be checked using the principle of homogeneity in dimensions.State the principle of homogeneity |
| Answer» SOLUTION :In any correct EQUATION, the DIMENSIONS of all the TERMS must be identical. | |
| 14612. |
If a satellite orbits as close to the earth's surface as possible, (a) its speed is maximum (b) time period of its rotation is minimum. (c) the total energy of the 'earth plus satellite' system is minimum (d) the total energy of the 'earth plus satellite' system is maximum |
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Answer» only a is TRUE |
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| 14613. |
Which physical quantity is conserved when a planet revolves around the sun? |
| Answer» SOLUTION :ANGULAR MOMENTUM of planct. | |
| 14614. |
A carpet of mass M made of inextensible material is rolled along its length in the form of a cylinder of radius R and is kept on a rough floor. The carpet starts unrolling without sliding on the floor when a negligibly small push is given to it. Calculate the horizontal velocity of the axis of the cylindrical part of the carpet when its radius reduces to (R)/(2). |
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| 14615. |
A man runs towardsmirror at a speed of 15m//s the speed of image with respect to man is |
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Answer» `7.5m//s` |
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| 14616. |
When a gas in a closed vessel was heated so as to increase its temperature by 5^(@)C, there occurred an increase of 1% in its pressure, the original temperature of the gas was ……….. . |
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Answer» `50^(@)C` |
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| 14617. |
A piece of ice is floating on a liquid of density 1.5g*cm^(-3) kept in a beaker. Will there be any change in the level of the liquid in the beaker as the piece of ice melts completely? |
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Answer» Solution :If the piece of ice melts completely, then the level of the liquid in the BEAKER will rise. Let the mass of the piece of ice be m. So, the mass of the liquid displaced is also m. `therefore` Volume of displaced liquid, `V_(1)=m/rho_(l)" "[rho_(l)="density of the liquid"]` As the piece of ice melts completely, the mass of water formed = m. But the volume of that water, `V_(2)=m/rho_(w)=m" "[rho_(w)="density of water"]` According to QUESTION, `rho_(l)gtrho_(w)`, so `V_(2)gtV_(1)`. HENCE, the level of liquid in the beaker will rise. If the liquid is IMMISCIBLE in water, then water will float above the liquid. |
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| 14618. |
(A) : Systematic errors are due to a definite cause and can be minimised. (R) : Random errors are due to unknown reasons and can be completely eliminated. |
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Answer» Both (A) and (R) are TRUE and (R) is the correct EXPLANATION of (A) |
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| 14619. |
(A) : Heavy boxes are loaded along with empty boxes on a cart. Heavy boxes should be kept at the centre of gravity of the cart, form more stability.(R ) : The vertical line passing through the centre of gravity should fall within the base of cart for stability. |
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Answer» Both 'A' and 'R' and true and 'R' is the CORRECT EXPLANTATION of 'A' |
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| 14620. |
A broad gauge train runs at a speed of 72 km/h on a curved track of radius of curvature 1 km. Find the elevation of the outer rail above the inner rail so that there may be side-pressure on the rails ? Distance between the rails is 1.7 m. |
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Answer» Solution :The ELEVATION of outer rail over the inner rail is `h = (V^(2)L)/(rg) = (20 xx 20 xx 1.7)/(1000 xx 9.8) = 0.0694 m` |
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| 14621. |
Select the odd man out from the following : |
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Answer» ANGULAR acceleration |
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| 14622. |
A solid sphere of mass I kg, radius 10 cm rolls down an inclined plane of height 7 m. The velocity of its centre as it reaches the ground level is |
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Answer» 7 m/s For a solid SPHERE , `(k^2)/(R^2) = (2)/(5), v = sqrt((2 xx 10 xx 7)/((1 + (2)/(5)))) = 10 ` m/s |
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| 14623. |
A 4 kg mass and a 1 kg mass are moving with equal K.E.The ratio of their momentum is |
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Answer» `1:2` |
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| 14624. |
Two bodies are thrown with the same initial velocity at angle alpha and (90-alpha) to the horizon. What is the ratio fo the maximum heights reached by the bodies. |
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| 14625. |
A shell of mass m in flight explodes into three equal fragments. One of the fragment reaches the ground earlier than the other fragments. The acceleration of the centre of mass of the shell system just after one reaches ground is |
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Answer» g |
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| 14626. |
A body is projected from height of 60 m with a velocity 10 ms^(-1) at angle 30^(0) is horizontal. The time of flight of the body is [g = 10ms^(-2)] |
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Answer» 1 s |
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| 14627. |
A container contains liquid upto height H and kept on a horizontal frictionless surface .At t=0, the container is given a constant acceleration a_0 along positive x-axis.the pressure at point P depends upon : |
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Answer» <P>Only on the X-co-ordinate of the POINT P |
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| 14628. |
If gamma=C_P/C_V fora gas and R is universal gas constant then select the incorrect pair of the following. |
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Answer» For monoatomic MOLECULE `gamma= 5/2 R and ` for diatomic molecule `gamma=7/2R.` |
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| 14629. |
Is pressure a vector ? Give reason . |
| Answer» Solution :No, PRESSURE is always taken to be NORMAL to the PLANE of the areaon which it is acting . As this direction is unique , it does needany specification . So pressure is not a VECTOR . | |
| 14630. |
In a double star system two stars of masses m_1 and m_2 seperated by a distance .d. rotates about their centre of mass. Then the common angular velocity and time period is |
Answer» Solution : The GRAVITATIONAL force between the masses provides the necessary certripetal force `(Gm_1m_2)/d^2=m_1r_1omega^2 to` (1) The DISTANCE of centre of mass from `m_1` is `r_1= (m_2d)/(m_1+m_2) to` (2) From (1) and (2) `(Gm_1m_2)/d^2=(m_1m_2d)/(m_1+m_2). omega^2` `omega^2=(G(m_1+m_2))/d^3` (or) `omega=sqrt((G(m_1+m_2))/d^3)` |
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| 14631. |
What effect the following changes will makes to the range, sensitivity and responsiveness of a mercury in glass thermometer – (a) Increase in size of the bulb. (b) Increase in diameter of the capillary bore. (c) Increase in length of the stem. (d) Use of thicker glass for the bulb. |
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Answer» |
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| 14632. |
If a light ray incidents normally an one of the faces of the prism of refractive index 2 and emergent ray just grazes the second face of the prism, then the angle of deviation is |
| Answer» Answer :C | |
| 14633. |
Calculate the quantity of heat required to convert 10^(-2) Kg of ice at 0^(0)C to steam at 100^(0)C. |
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| 14634. |
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 power 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. |
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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`. |
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| 14635. |
Two liquids of masses M_1 and M_2 and specific heats S_1 and S_2 respectively are mixed . The specific heat of the mixture is |
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Answer» `(M_1S_1+M_2S_2)/(M_1+M_2)` |
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| 14636. |
If a gymnast sitting on a rotating stool, with his arms out stretched, suddenly lowers his hands, what will happen? |
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Answer» the angular VELOCITY decreases Sicne `I=MR^(2)` |
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| 14637. |
Boltzmann constant and Planck.s constant differ in the dimensions of |
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Answer» MASS and Time |
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| 14638. |
If a position vector of a point is vecr=7hati+3hatj+hatk and force acting on it is vecF=-3hati+hatj+5hatk then findtorque. |
| Answer» SOLUTION :`14hati-38hatj+16hatk`, MAGNITUDE 43.52 UNIT | |
| 14639. |
A bottel weighing 220 g and of area of cross-section 50 cm^(2), and height 4 cm oscillats on the surface of water in vertical position. Its frequency of oscillation is : |
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Answer» `2.5 Hz` `A h rhog= mg` (or) `h=(m)/(A RHO)` Now time PERIOD, `T=2pi sqrt((h)/(g))` (or) `f=(1)/(T)=(1)/(2pi) sqrt((g)/(h))` `=(7)/(2xx22) sqrt((980)/(4))` `[ :. G=980 cm//s^(2), h= 4cm]` `=2.5 Hz` |
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| 14640. |
What is the area under the graph of F to x ? (F = external force , x = change of spring length ) |
| Answer» SOLUTION :NET WORK DONE(W) | |
| 14641. |
Heat engine is a device used to convert……………….. Engergy into ………………. Energy |
| Answer» SOLUTION :HEAT ENERGY into MECHANICAL energy | |
| 14642. |
If for hydrogen C_(p)-C_(v)=m and for nitrogen C_(p)-C_(v)=n,Where C_(p)and C_(v)refer to specific heats per unit mass respectively at constant pressure and constant volume, the relation between m and n is (molecular weight of hydrogen = 2 and molecular weight or nitrogen = 14) |
| Answer» Answer :C | |
| 14643. |
A tower 100m tall at a distance of 3km is seen through a telescope having objective of focal length 140cm and eyepiece of focal length 5cm. What is the size of final image if it is 25cm from the eye? |
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Answer» SOLUTION :For objective LENS `1/v-1/(3 times 10^5)=1/140` i.e., `v=140 cm =f_0` So `m_0=v/u= 140/(-3 times 10^5)=- 14/3 times 10^-4` and as FINAL IMAGE is at least distance of distinct vision so for eye lens, we have `1/(-25)-1/u_e=1/5 ` i..e, `u_e=- 25/6` So `m_e=v_e/u_e= (-25)/((-25/6))=6` and hence, `m=m_0 times m_e= - 14/3 times 10^-4 times 6` But as `m=(I/O)` `I=m times O= -28 times 10^-4 times (100 times 10^2)=-28 cm` Negative sign implies that image is inverted. |
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| 14644. |
Three tortoises are located at the vertices of an equilateral triangle whose side equals a They all start moving simultaneously with velocity v constant in modulus with the first tortoise heading continually for the second , the second for the third and the third for the first . They will meet after time |
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Answer» |
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| 14645. |
When a train approaches a listener , the apparent frequency of the whistle is 100 Hz , while the frequency appears to be 50 Hz when the train recedes . Calculate the frequency when the listener is in the train . |
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Answer» Solution :If the listener is in the train , he will listen to the actual frequency of the whistle (n) . If V is the velocity of SOUND , ` u_(s)` is the velocity of the source and ` u_(o) ` is the velocity of the listener , the apparent frequency , ` n. (V + u)/(V - u_(s)) xx n ` In the given problem , inboth the cases the listener is at rest So ` u_(o) = 0 ` In the firstcase , the motion of the train is towards the listener . so , ` u_(s) ` is positive. Again in hte second case , the train recedes from the listener . So , ` u_(s) ` is negative . Therefore , in the two cases we have ` 100 = (V + 0)/(v - u_(s)) xx n ` or ` (V) /(V - u_(s)) xx n = 100` ...(1) and ` 50 = (V + 0)/(V - (-u_(s))0 xxn ` or ` (V)/(V + u_(s)) xx n = 50 ` ...(2) From equation (1) , ` (n) /(100) = (V - u_(s)) /(V) = 1- (u_(s))/(V)or , (u_(s))/(V) = 1 - (n) /(100)=(100- n)/(100)` From equation (2) , `(n)/(50) = (V + u_(s))/(V) = 1 + (u_(s))/(V) or , (u_(s))/(V) = (n) / (50)- 1 = (n - 50)/(50) ` ` therefore (100 - n)/(100) = (n-50)/(50)or , 100 - n = 2n - 100` 3N = 200 or , n = 66(2)/(3) `Hz . |
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| 14646. |
A uniform cube of side 'a' and mass m rests on a rough horizontal table. A horizontal force F is applied normal to one of the faces at a point directly below the centre of the face, at a height a//4 above the base. a. What is the minimum value of F for which the cube begins to tip about an edge? b. What is the minimum value of its so that toppling occurs? c. If mu=mu_("min") find minimum force for topping. d. Find minimum mu_(s) so that F_("min") can cause toppling. |
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Answer» HENCE `F(a/4)gtmg(a/2)`  or `Fgtmg` Therefore minimum value of `F` is `2mg` b. In thiscase SINCE it is not acting at `COM`, toppling can occur even after body started sliding because increasing the torque of `F` about `COM`. Hence `mu_(min)=0`, c. Now body is sliding before toplling `O` is not `IAR`, torque equation can not be APPLIED across it. It can now be applied about `COM`. `Fxxa/4=Nxxa/2` ......i `N=mg` ...........ii From i and ii `F=2mg` d. `Fgt2 mg` ............iii from sol a `N=mg` `Fmu_(s)N=mu_(s)mg`.........iv from i and ii `mu_(s)=2`.......v |
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| 14647. |
For a gas, the difference between two specific heats is 5000 "J/mole-"^@C. If the ratio of specific heats is 1.6, the two specific heats are : |
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Answer» `C_p = 1.33 XX 10^4, C_v = 2.66 xx 10^4` |
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| 14648. |
A rod PQ of mass M and length L is hinged at end P. The rod is kept horizontal by a mass less than string tied at a point Q as shown in figure. When string is cut, the initial acceleration rod is: |
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Answer» `(3g)/(2L)` `I=(ML^(2))/3` `L/2Mg=(ML^(2))/3xxalpha` `:.alpha=(3g)/(2L)` |
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| 14649. |
A body executing SHM at a displacement 'x' its PE is 16J, and at displacement 'y' its PE is 25J. The PE at a displacement (x+y) is |
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Answer» 49J |
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| 14650. |
What is meant by statevariable ? Giveexample |
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Answer» Solution :In THERMODYNAMICS, the state of a thermodynamic SYSTEM is represented by a SET of variables called thermodynamic variables. Examples: PRESSURE, temperature, volume and internal ENERGY etc. |
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