InterviewSolution
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InterviewSolution
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.
| 101. |
Water pours out rate of Q from a tap, into a cylindrical vessel of radius r. The rate at which the height of water level rises the height is h, isA. `(Q)/(pi rth)`B. `(Q)/(pi r^(2))`C. `(Q)/(2 pi r^(2))`D. `(Q)/(pi r^(2) h)` |
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Answer» Correct Answer - B |
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| 102. |
A block of volume `V` and density `sigma_(b)` is placed in liquid of density `sigma_(1)(sigma_(1) gt sigma_(b))`, then block is moved upward upto a height `h` and it is still in liquid. The increase in gravitational energy of the block is :A. `sigma_(b) Vgh`B. `(sigma_(b) + sigma_(l)) Vgh`C. `(sigma_(b) - sigma_(l)) Vgh`D. None of these |
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Answer» Correct Answer - C |
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| 103. |
What force must be applied to detach two wetted photographic plates `(9 cm xx 12 cm)` in size from each other without shifting them. The thickness of water between the plates is 0.05 mm. Surface tension of water is 0.073 N/m.A. `31.5 N`B. `16.5 N`C. `40.5 N`D. `20.0 N` |
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Answer» Correct Answer - A |
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| 104. |
The strain stress curves of three wires of different materials are shown in the figure. P, Q and R are the elastic limits of the wires. The figure shown thatA. Elasticity of wire P is maximumB. Elasticity of wire Q is maximumC. Tensile strength of R is maximumD. None of the above is true. |
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Answer» Correct Answer - D As stress is shown of x-axis and strain on y-axis So we can say that `Y=cottheta=(1)/(tantheta)=(1)/(slope)` so elasticity of wire P is minimum and of wire `R` is maximum. |
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| 105. |
The metal cube of side 10 cm is subjected to a shearing stress of `10^(4)Nm^-2`. The modulus of rigidiy if the top of the cube is displaced by 0.05 cm with respect to its bottom isA. `2xx10^6Nm^-2`B. `105Nm^-2`C. `1xx10^(7)Nm^-2`D. `4xx10^5Nm^-2` |
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Answer» Correct Answer - A Here, `l=10cm`,`trianglel=0.05cm` Shearing stress`=10^4Nm^-2` `eta=(sheari ng stress)/(sheari ng strai n)=(10^4))/(0.005)=2xx10^6Nm^-2` |
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| 106. |
Two strips of metal are riveted together at their ends by four rivets, each of diameter 6 mm. Assume that each rivet is to carry one quarter of the load. If the shearing stress on the rivet is not to exceed `6.9xx10^7Pa`, the maximum tension that can be exerted by the riveted strip isA. `2xx10^3N`B. `3.9xx10^3N`C. `7.8xx10^3N`D. `15.6xx10^3N` |
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Answer» Correct Answer - C Radius of a rivet `r=(6)/(2)mm=3mm=3xx10^-3m` maximum loa on a rivet `=`maximum stress`xx`area of cross section `=6.9xx10^7xxpi(3xx10^-3)^2` `=1950N` Maximum tension that can be exerted by rivet strip `=4xx1950N=7800N=7.8xx10^3N` |
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| 107. |
A block of volume V and density `rho` is floating in a liquid of density `2 rho` filled in a vessel. Now the vesset starts falling freely with acceleration `g`. Then the volume of block inside the liquid in the falling condition isA. VB. `V//2`C. arbitrayD. zero |
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Answer» Correct Answer - C |
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| 108. |
In two identical communicating vessel we poured water (see picture). In one of them we put an ice ball of volume `V=100 cm^(3)` which gets exactly half immersed in the water. The density of water `rho_(w)=1000kg//m^(3)` the density of ice `rho_(i)=900kg//m^(3)` Select the correct statement (s). Soon after placing the ice ball in left vessel.A. The volume of water flowing to the right vessels is more than 25cc.B. The volume of water flowing to the right vessels is less than 25cc.C. The ice ball is resting on the bottom of vessel.D. The ice ball is floating on the water surface. |
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Answer» Correct Answer - A::C |
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| 109. |
These questions consist two statements each, printed as Assertion and reason, while answering these question you are required to choose any one of the following four responsis: (a) If both the assertion and reason are true and reason is a true explanation of the assertion. (b) If both the assertion and reason are true but the reason is not the correct explanation of assertion. (c ) If the assertion is true but reason is false. (d) If both the assertion and reason are false. Q. Assertion: Railway tracks are laid on small-sized wooden sleepers. Reason: Small sized wooden sleepers are used so that rails exert more pressure on the railway track. due to which rail does not leave the track. |
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Answer» Correct Answer - D Railways track are laid on large-sized wooden sleepers. Due to large sized sleepers the weight of rail act on the large area. Hence, the pressure exerted is reduced appreciably. |
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| 110. |
These questions consist two statements each, printed as Assertion and reason, while answering these question you are required to choose any one of the following four responsis: (a) If both the assertion and reason are true and reason is a true explanation of the assertion. (b) If both the assertion and reason are true but the reason is not the correct explanation of assertion. (c ) If the assertion is true but reason is false. (d) If both the assertion and reason are false. Q. Assertion: Bulk modulus of elasticity (K) represents incompressibility of the material. Reason: Bulk modulus of elasticity is proportional to change in pressure. |
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Answer» Correct Answer - A Bulk modulus of elasticity measures how good the body is to regain its original volume on being compressed. Therefore, it represents incompressibility of the material, `K=(-PV)/(triangleV)` where `P` is increase in pressure, `triangleV` is change in volume. |
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| 111. |
Three liquids of densities `rho_1`,`rho_2` and `rho_3` (with `rho_1gtrho_2gtrho_2)` having the same value of surface tension `T`, rise to the same height in three identical capillaries. The angles of contact `theta_1`,`theta_2` and `theta_3` obeyA. `(pi)/(2)lttheta_1lttheta_2ltthetaltpi`B. `pigttheta_1gttheta_2gttheta_3gt(pi)/(2)`C. `(pi)/(2)gttheta_1gttheta_2gttheta_3ge0`D. `0letheta_1lttheta_2lttheta_3lt(pi)/(2)` |
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Answer» Correct Answer - D `h=(2Tcostheta)/(rhogr)` as r,h, T are same `implies(costheta)/(rho)=`constant `implies=(costheta_1)/(rho_1)=(costheta_2)/(rho_2)=(costheta_3)/(rho_3)` as `rho_1gtrho_2gtrho_3` `impliescostheta_1gtcostheta_2gtcostheta_3` `impliestheta_1lttheta_2lttheta_3` As water rises `impliestheta` must be acutee So, `(0letheta_1lttheta_2lttheta_3ltpi)/(2)` |
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| 112. |
The execc pressure inside the first soap bubble is three times that inside the second bubble. Then the ratio of the volumes of the first and second bubbles isA. `1:3`B. `1:9`C. `1:27`D. `3:1` |
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Answer» Correct Answer - C `(r_1)/(r_2)=(p_2)/(p_1)=(1)/(3)` , `(V-1)/(V_2)=(r_1^3)/(r_2^3)=(1)/(27)` |
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| 113. |
The surface of soap solution is `25xx10^-3Nm^-1`. The excess pressure inside a soap bubble of diameter 1 cm isA. 10 PaB. 20 PaC. 5 PaD. none of the above |
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Answer» Correct Answer - B Excess pressure `triangleP=(4T)/(r )` `=(4xx2xx25xx10^-3)/(1xx10^-2)` `=20(N)/(m^2)=20Pa` (as `r=(d)/(2)`) |
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| 114. |
The diagram shoes stress v/s strain curve for the materials A and B. From the curves we infer thatA. A is brittle but B is ductileB. A is ductile and B is brittleC. Both A and B are ductileD. Both A and B are brittle |
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Answer» Correct Answer - B In ductile materials, yield point exists while in brittle material, failure would occur without yielding. |
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| 115. |
The diagram shoes stress v/s strain curve for the materials A and B. From the curves we infer thatA. A is brittle but B is ductileB. A is ductile and B is brittleC. Both A and B are ductileD. Both A and B are brittle |
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Answer» Correct Answer - B In ductile materials, yield point exist whil in Brittle material, failure would occur without yielding. |
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| 116. |
if `rho` is the density of the meterial of a wire and `sigma` is the breaking stress. The greatest length of the wire that can hang freely without breaking isA. `(2 sigma)/(rho g)`B. `(rho)/(sigma g)`C. `(rho g)/(2 sigma)`D. `(sigma)/(rho g)` |
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Answer» Correct Answer - D |
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| 117. |
A certain number of spherical drops of a liquid of radius `r` coalesce to form a single drop of radius `R` and volume `V`. If `T` is the surface tension of the liquid, thenA. energy `= 4VT((1)/(r)-(1)/(R))` is releasedB. energy `= 3VT((1)/(r)+(1)/(R))` is absorbedC. energy `= 3VT((1)/(r)-(1)/(R))` is releasedD. energy is neither released nor absorbed |
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Answer» Correct Answer - c As energy released `= (A_(f)-A_(i))T` where, `A_(i) = 4pi R^(2) = (3)/(3) xx 4pi (R^(3))/(R) = (3V)/(R)` and `A_(f) = 4pi r^(2) = (V)/((4)/(3)pi r^(2))4pir^(2) = (3V)/(r)` `:.` Energy released `= 3VT[(1)/(r)-(1)/(R)]` |
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| 118. |
If a million tiny droplets of water of the same radius coalesce into one larger drop, the ration of the surface energy of the large drop to the total surface energy of all the droplets will beA. `1 : 10`B. `1 : 10^(2)`C. `1 : 10^(4)`D. `1 : 10^(6)` |
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Answer» Correct Answer - B |
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| 119. |
Force constant of a spring `(k)` is anonymous toA. `(YA)/(L)`B. `(YL)/(A)`C. `(AL)/(Y)`D. `ALY` |
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Answer» Correct Answer - A |
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| 120. |
A solid shell loses half of its weight in water. Relative density of shell is 5.0 What fraction of its volume is hollow ?A. `(3)/(5)`B. `(2)/(5)`C. `(1)/(5)`D. `(4)/(5)` |
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Answer» Correct Answer - A |
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| 121. |
The pressure inside a small air bubble of radius `0.1`mm situated just below the surface of water will be equal to [Take surface tension of water `70xx10^-3Nm^-1` and atmospheric pressure`=1.013xx10^5Nm^-2`]A. `2.954xx10^3Pa`B. `1.027xx10^3Pa`C. `1.027xx10^5Pa`D. `2.054xx10^5Pa` |
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Answer» Correct Answer - C Excess pressure inside the air bubble`=(2T)/(r )` `impliesP_(in)-P_(out)=(2T)/(r )=(2xx70xx10^-3)/(0.1xx10^-3)=1400Pa` `impliesP_(in)=1400+1.013xx10^5` `=0.014xx10^5+1.013xx10^5=1.027xx10^5Pa` |
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| 122. |
The correct curve between the height or depression `h` of liquid in a capillary tube and its radius isA. B. C. D. |
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Answer» Correct Answer - B `h=(2Tcostheta)/(rdg)` `because` `hprop(1)/(r )`, so the graph between `h` and `r` will be rectangular hyperbola. |
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| 123. |
A U-tube containing a liquid moves with a horizontal acceleration a along a direction joining the two vertical limbs. The separation between these limbs is d. The difference in their liquid levels isA. `ad//g`B. `2da//g`C. `da//2g`D. `d tan (a//g)` |
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Answer» Correct Answer - A |
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| 124. |
For a satellite to orbit around the earth, which of the following must be true?A. It must be above the equator at some time.B. It cannot pass over the poles at any time.C. Its height above the surface cannot exceed 36,000 km.D. Its period of rotation must be `gt 2pisqrt(R//g)`. |
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Answer» Correct Answer - A::D |
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| 125. |
In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c ) If assertion is true but reason is false. (d) If assertion and reason are false. Q. Glassy solids have sharp meting point. Reason: The bonds between the stoms of glassy solids get broken at the same temperature. |
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Answer» Correct Answer - D In a glassy solid, i.e., amorphous solid, the various bonds between the atoms or ions or molecules of a solid are not equally string. Different bonds are broken at different temperature. Hence there is no sharp melting point for a glassy solid. |
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| 126. |
Four uniform wires of the same material are stretched by the same force. The dimensions of wire are as given below. The one which has the minimum elongation has:A. radius 3 mm, length 3 mB. radius 0.5 mm length 0.5 mC. radius 2 mm,length 2 mD. radius 3 mm, length 2 m |
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Answer» Correct Answer - D `trianglel=(Fl)/(pir^2Y)impliestrianglelprop(l)/(r^2)` Only option radius 3 mm length 2 m is satisfying the above relation. |
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| 127. |
The length of a metal wire is `l_1` when the tensionin it is `T_1 and is l_2` when the tension is `T_2`. The natural length of the wire isA. `(T_2)/(T_1)(l_1+l_2)`B. `T_2l_1+T_2l_2`C. `(l_1T_2-l_2T_1)/(T_2-T_1)`D. `(l_1T_2+l_2T_1)/(T_2+T_1)` |
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Answer» Correct Answer - C `Y=(Fl)/(atrianglel)` `Y`, `l` and `a` are constants `(Fl)/(trianglel)=`constant or `trianglelpropF` Now, `l_1lpropT_1` and `l_2-lT_2` Dividing, `(l_1-1)/(l_1-1)=(T_1)/(T_2)` or `l_1T_2-lT_2=l_2T_1-lT_1` or `l(T_1-T_2)=l_2T_1-l_1T_2` or `l=(l_1T_2-l_1T_2)/(T_1-T_2)` or `l=(l_1T_2-l_2T_1)/(T_3-T_1)` |
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| 128. |
Two small satellies move in a circular orbits around the earth, at disatnce `r` and `(r + dr)` from the centre of the earth. Their time periods of rotation ate `T` and `T + dT (Delta r lt lt r, DeltaT lt lt T)`. ThenA. `Delta T = (3)/(2)T(Delta r)/(r)`B. `Delta T = -(3)/(2)T(Delta r)/(r)`C. `Delta T = (2)/(3)T(Delta r)/(r)`D. `Delta T = T(Delta r)/(r)` |
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Answer» Correct Answer - A |
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| 129. |
A point `P` lies on the axis of a fixed ring of mass `M` and radius `a`, at a distance `a` from its centre `C`. A small particle starts from `P` and reaches `C` under gravitational attraction only. Its speed at `C` will be.A. `sqrt((2GM)/(a))`B. `sqrt((2GM)/(a)(1-(1)/(sqrt()2)))`C. `sqrt((2GM)/(a)(sqrt()2-1))`D. Zero |
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Answer» Correct Answer - B |
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| 130. |
P is a point at a distance r from the centre of a spherical shell of mass M and radius a, where `r lt a`. The gravitational potential at P isA. `-(GM)/(r)`B. `-(GM)/(a)`C. `-GM(r)/(a^(2))`D. `-GM((a-r)/(a^(2)))` |
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Answer» Correct Answer - B |
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| 131. |
The end of a capillary tube is immersed into a liquid. Liquid slowly rises in the tube up to some height. The capillary-fluid systemA. will absorb heatB. will release heatC. will not be involved in any heat transferD. nothing can be said |
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Answer» Correct Answer - B |
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| 132. |
A container is partially filled with a liquid of density `rho_2` A capillary tube of radius r is vertically inserted in this liquid. Now another liquid of density `rho_1(rho_1ltrho_2)` is slowly poured in the container to a height h as shown. There is only denser liquid in the capillary tube. The rise of denser liquid in the capillary tube is also `h`. Assuming zero contact angle, the surface tension of heavier liquid isA. `rrho_2gh`B. `2pirrho_2gh`C. `(r )/(2)(rho_2-rho_1)gh`D. `2pir(rho_2-rho_1)gh` |
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Answer» Correct Answer - C `P_0+rho_1gh-rho_2gh+(2T)/(r )=P_0` `impliesT=(r )/(2)(rho_2-rho_1)gh` |
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| 133. |
A capillary tube of radius `r` is immersed in a liquid. The liquid rises to a height `h`. The corresponding mass is `m`. What mass of water shall rise in the capillary if the radius of the tube is doubled?A. `M`B. `2M`C. `(M)/(2)`D. `4M` |
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Answer» Correct Answer - B Mass of liquid in capillary tube `M=piR^2Hxxrho` `because` `MpropR^2xx((1)/(R ))` `MpropR`. If radius becomes double then mass will become twice. |
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| 134. |
Consider the barometer shown in figure. Density of mercury is `rho`. A small hole is made at point S as shown. The mercury come out from this hole with speed `v` equal to A. `sqrt(2gh)`B. `sqrt(2gH)`C. `sqrt(2g (H - h))`D. None of these |
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Answer» Correct Answer - D |
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| 135. |
A cubical block of wood of specific gravity `0.5` and chunk of concrete of specific gravity `2.5` are fastened together. the ratio of mass of wood to the mass of concrete which makes the combination to float with entire volume of the combination submerged in water isA. `(5)/(3)`B. `(6)/(5)`C. `(5)/(2)`D. `(4)/(3)` |
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Answer» Correct Answer - A |
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| 136. |
The value V in the bent tube is initially kept closed. Two soap bubbles A (smaller) and B (larger) are formed at the two open ends of the tube. V is now opened, and air can flow freely between the bubbles.A. There will be no change in the sizes of the bubbles.B. The bubbles will become of equal size.C. A will become smaller and B will become larger.D. The sizes of the two bubbles will become interchanged. |
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Answer» Correct Answer - C |
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| 137. |
A uniform rod of length 2.0 m specific gravity 0.5 and mass 2 kg is hinged at one end to the bottom of a tank of water (specific gravity = 10) filled upto a height o f 1.0 m as shown in figure. Taking the case `theta =- 0^(@)` the force exerted by the hings on the rod is `(g = 10 m//s^(2))` A. 10.2 N upwardsB. 4.2 N downwardsC. 8.3 N downwardsD. 6.2 N upwards |
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Answer» Correct Answer - C |
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| 138. |
A barometer tube reads 76 cm of mercury. If the tube is gradually inclined at an angle of `60` with vertical, keeping the open end immersed in the mercury reservoir, the length of the mercury column will beA. 152 cmB. 76 cmC. 38 cmD. `38 sqrt3 cm` |
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Answer» Correct Answer - A |
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| 139. |
A container contains three liquds as shown in the figure. The specific gravity of liquid 1 and liquid 2 are 0.8 and 1.2 respectively. A small hole having area `10^(-6) m^(2)` at point P is as shown in the figure. Initially hole is closed. The cross-sectional area of container is `50 cm^(2)`. assume all liquids ae ideal and neglect any type of friction between liquid and container. (Given that `g=9.8 m//s^(2)` and `h=28 cm`) The value of `h_(2)//h_(1)` isA. `9//5`B. `20//7`C. `40//21`D. `40//7` |
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Answer» Correct Answer - C |
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| 140. |
A small block of wood of specific gravity 0.5 is subnerged at a depth of 1.2 m in a vessel filled with water. The vessel is accelerated upwards with an acceleration `a_(0) = (g)/(2)`. Time taken by the block to reach the surface, if it is released with zero initial velocity is `(g = 10 m//s^(2))`A. 0.6 sB. 0.4 sC. 1.2 sD. 1 s |
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Answer» Correct Answer - B |
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| 141. |
A tank contains water and mercury as shown in figure. An iron cube of edge `d=6` cm is in equilibrium as shown. (density of iron `=7.8xx10^(3) kg//m^(3)`, density of mercury `=13.6xx10^(3) kg//m^(3)`, density of water `=10^(3) kgm^(3)`)(Neglect the atmospheric pressure) Time period of small oscillations of block isA. `2pi sqrt((drho_(Fe))/((rho_(Hg)-rho_(W))g))`B. `2pi sqrt((drho_(Fe))/((rho_(Hg)+rho_(W))g))`C. `2pi sqrt((d rho_(Fe))/(rho_(Hg)g))`D. `2pi sqrt((d rho_(Fe))/(rho_(w)g))` |
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Answer» Correct Answer - A |
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| 142. |
A glass tube `80 cm` long and open ends is half immersed in mercury. Then the top of the tube is closed and it is taken out of the mercury. A column of murcury `20 cm` long then remains in the tube. The atmospheric (in cm of Hg) is (assume temperature to be constant )A. 75B. 30C. 60D. 90 |
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Answer» Correct Answer - C |
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| 143. |
The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. Ration of density of mercury to that of air is `10^(4)`. The height of the hill isA. 250 mB. 2.5 kmC. 1.25 kmD. 750 m |
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Answer» Correct Answer - B |
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| 144. |
A container contains three liquds as shown in the figure. The specific gravity of liquid 1 and liquid 2 are 0.8 and 1.2 respectively. A small hole having area `10^(-6) m^(2)` at point P is as shown in the figure. Initially hole is closed. The cross-sectional area of container is `50 cm^(2)`. assume all liquids ae ideal and neglect any type of friction between liquid and container. (Given that `g=9.8 m//s^(2)` and `h=28 cm`) At some instant, hole is opened. the speed of water coming out from hole just after the opening of hole isA. 7.84 m/sB. 3.92 m/sC. 1.96 m/sD. None of these |
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Answer» Correct Answer - B |
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| 145. |
A tank contains water on top of mercury . A cube of iron, 60mm along each edge, is sitting upright in equilibrium in the liquids. Find how much of it is in each liquid. The densities of iron and mercury are `7.7xx10^(3)kg//m^(3)` and `13.6xx10^(3) kg//m^(3)` respectively A. 2 cmB. 4.5 cmC. 3.24 cmD. 2.5 cm |
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Answer» Correct Answer - C |
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| 146. |
When water droplets merge to form a bigger dropA. energy is liberatedB. energy is absorbedC. neither liberated nor absorbedD. Some mass is converte into energy |
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Answer» Correct Answer - A When two droplets merge with each other, their surface energy decreases. `W=T(triangleA)=`(negative) i.e., Energy is released. |
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| 147. |
Two mercury drops each of radius r merge to form a bigger drop. Calculate the surface energy released.A. `8pir^2sigma-4xx2^((2)/(3))pir^2sigma`B. zeroC. negativeD. `4pir^2sigma-8xx2^((1)/(3))r^2sigma` |
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Answer» Correct Answer - A `2xx(4)/(3)pir^2=(4)/(3)piR^3` or `R=2^((1)/(3))r` Final surface energy`=4piR^2sigma=4pi2^((2)/(3))r^2sigma` Initial surface energy`=2xx4pir^2sigma` Energy released`=[8pir^2-4xx2^((2)/(3))pir^2]sigma` |
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| 148. |
A lead shot of a 1mm diameter falls through a long column of glycerine.The variation of its velocity `v` with distance covered is represented by,A. B. C. D. |
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Answer» Correct Answer - A After travelling certain distance the net force on lead is zero. The layer of glycerine in contact with lead shot tends to move with velocity of lead shot, a stage is finally reached when the opposing viscous force becomes equal to the effective force driving the ball. The net force on the shot is not zero and lead shot attains a constant velocity called the terminal velocity. |
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| 149. |
There is a 1mm thick layer of glycerine between a flat plate of area `100cm^(2)` and and a big plate. If te coefficient of viscosity of glycerine is `1.0kg//m-sec`, then how much force is required to move the plate with a velocity of 7 cm/sec.A. 3.5 NB. 0.7 NC. 1.4 ND. None of these |
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Answer» Correct Answer - B |
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| 150. |
In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as (a) If both assertion and reason are true and reason is the correct explanation of assertion. (b) If both assertion and reason are true but reason is not the correct explanation of assertion. (c ) If assertion is true but reason is false. (d) If assertion and reason are false. Q. Assertion: Steel is more elastic than rubber. Reason: Under a given deforming force steel is deformed less than rubber. |
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Answer» Correct Answer - A The internal restoring force acting per unit area of cross-section of the deformed body is called stress. Also elasticity is the property of the material of a body by virtue of which it opposes any change in its size or shape. Greater the force required more elastic the body is. Hence, steel is more elastic than rubber. |
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