Saved Bookmarks
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.
| 13001. |
A particle is projected at an angle theta with the horizontal . If angle of elevation of highest point of trajectory is phi when seen from point of projection, then |
|
Answer» `tan PHI =2 tan phi`  From the FIGURE, `tan phi =(H)/(R//2)=(2H)/(R)=((2(u^(2) sin^(2)theta)/(2g))/(u^(2) sin 2 theta))/(g)` `tan phi =(sin^(2) theta)/(sin 2THETA)=(sin ^(2)theta)/(2 sin theta COS theta)=(1)/(2)tan theta` Hence, option (c) is correct . |
|
| 13002. |
Can a liquid offer permanent resistance to shearing stress? |
| Answer» SOLUTION :No. It cannot offer PERMANENT RESISTANCE to forces to change its SHAPE. | |
| 13003. |
Given a+b+c+d = 0 which of the following statement is incorrect |
|
Answer» a, b, C and d must each be a null vector. |
|
| 13004. |
A vesel of volume V = 5.0 litre contains 1.4 g of nitrogen at temperature, T = 1800 K. Find the pressure of the gas if 30% of its molecules are dissociated into atoms at this temperature. |
|
Answer» SOLUTION :Mass of molecular nitrogen Mass of atomic nitrogen `=30/100 times 1.4=0.42g` Number of moles of atomic nitrogen, `n_(1)=0.42/14=0.03` The PRESSURE of the gas = pressure exerted by molecular + pressure exerted by atomic nitrogen i.e., `P=P_(1)+P_(2)=(n_(1)RT)/V+(n_(2)RT)/V=((n_(1)+n_(2))RT)/V` `=((0.035+0.03) times8.31 times 1800)/(5 times 10^(-3))=1.94 times 10^(5)N//m^(2)`. |
|
| 13005. |
A pendulum is suspended in a stationary lift and its time period is T. what will be its time period when the lift goes up with uniform velocity ? |
| Answer» Solution :When the LIFT goes up with uniform velocity TENSION in the string T= mg. the value of g REMAINS unaffected. Hence the TIME period does not CHANGE. | |
| 13006. |
An aluminium sphere is dipped into water. Which of the following is true ? |
|
Answer» Buoyancy will be less in WATER at `0^(@)` C than that in water at `4^(@)` C . |
|
| 13007. |
A motorist moves along a circular track at 144kmh^(-1). The angle he should make with the vertical if the track is 880 m long is (g= 10ms^(-2)) |
|
Answer» `45^(@)` |
|
| 13008. |
The difference between the true value and the measured value of a quantity is known as……… |
|
Answer» ABSOLUTE ERROR |
|
| 13009. |
Statement I : In a standing wave on a string , the spacing between nodes is Delta x. If the tension in string is increased wave same as before , then the separation between nearest node and antinode will be Delta x. Statement II : Spacing between nodes ( consecutive) in the standing wave is equal to half of the wavelength of component waves. |
|
Answer» STATEMENT I is true , Statement II is true , Statement II is a correct explanation for Statement I. The spacing between two CONSECUTIVE nodes in STANDING waves is equal to half of wavelength of component waves before increasing the tension , then `Delta x = lambda//2`. After increasing the tension in string `Deltax'` ( spacing between different nodes) ` = ( 2 lambda)/(2) = 2 Delta x` ltbegt So , spacing between the node and antinode is `(Delta x')/(2) = Delta x` |
|
| 13010. |
A 20-0 litre bucket can be filled with water using a water hose 3-00 cm in diameter in 2 minutes. Calculate the speed with which the water leaves the hose. |
|
Answer» Solution : Volume of water FLOWING PER second `= ( 20 xx 10 ^(-3) m^(3))/( 2 xx 60 s) ` ` "" = 1.67 xx 10 ^(-4) m^(3)//s` Radius of the hose ` = r= 1.5 cm = 0.015 m` Speed of water flow `= v = ? ` ` "" AV= 1.67 xx 10 ^(-4)` `"" v= (1.67 xx 10 ^(-4))/(pi r ^(2)) = (1.67 xx 10 ^(-4))/( 3.14 xx (0.015)^(2))` `"" v= 0.24 m//s` |
|
| 13011. |
A uniform chain of length 2m is kept on a table such that a length of 60cm hangs freely from the edge of the table. The total mass of the chain is 4kg. What is the work done in pulling the entire chain onto the table? (g = 10 m//s^(2)) |
|
Answer» 7.2J |
|
| 13012. |
For isothermal change (DeltaP)/P is equal to |
|
Answer» `1/2gamma(DELTAV)/V` |
|
| 13013. |
A spring of force constant 1200 Nm^(-1) is mounted on a horizontal table and a mass of 3.0 kg of attached to the free and of the spring. The mass is made to rotate with an angular velocity of 10 rad/s. What is the elongation produced in the spring if its unstretched length is 60 cm ? |
| Answer» Solution :`m(l +x)omega^(2) = KX, x = mkomega^(2)lk-momega^(2) = 3 xx 0.60xx 10^(2)//1200 - 3 xx 10^(2) = 0.2 m` | |
| 13014. |
A wooden blocks is taken to the bottom of a deep column lake of watre and then released it rises up with a |
|
Answer» CONSTANT acceleration |
|
| 13015. |
For a particle executing SHM , which of the following statements is not correct? |
|
Answer» The total energy of a particle ALWAYS remains the same |
|
| 13016. |
A Spheremakes an inslastic collision with another sphere of same mass , then both the spheres are moving .The angle between theirdirection of motion will be …….. |
|
Answer» `0^(@)` |
|
| 13017. |
The length of a rod is 2.5 cm and diameter is 2.5mm. Find the volume of the rod with due consideration to significant figures. |
|
Answer» |
|
| 13019. |
Two bodies are thrown with the same initial velocity of 30 m/s. One at 17^(@), other at 73^(@) to the horizontal. The sum of the maximum heights reached by them is [g = 10 m//^(2)] |
|
Answer» 45m |
|
| 13020. |
A rubber ball takes 5 s to fall through a height of 0.5 m inside a large container containing water of specific gravity 1. Calculate the viscosity of water if mass of the ball is 1.24 xx 10^(-3) kg and diameter is 6.6 xx 10^(-3)m. |
|
Answer» |
|
| 13021. |
A long rod is heated from one end and the bar attains the conditions of steady state. (Given, emissivity of the material of rod = 0.9, coefficient of thermal conductivity of rod =100"Wm"^(-1)""^(0)C^(-1), radius of rod = 10cm = 0.1 m) This setup is placed in vacuum. If theta is temperature at steady state of any section of rod and (d^(2)theta)/(dx^(2))=2.N^(2).thetaxx10^(-2). Where, x is the distance of section from end, find the value of N. |
|
Answer» |
|
| 13022. |
A satellite of mass m revolves around the earth of radius R at a height x from its surface. If g is the acceleration due to gravity on the surface of the earth, the orbital speed of the satellite is ......... |
|
Answer» gx `(mv_0^2)/(R+x) = (GMm)/((R+x)^2)` `:. v_0 = sqrt((GM)/(R+x))= sqrt((rR^2)/(R+x))"" [ :. GM = gR^2]` `:. v_0 = [(gR^2)/(R+x)]^(1/2)` |
|
| 13023. |
A body of mass 6kg travelling with a velocity 10 m/scollides head - on and elastically with a body of mass 4kg travelling at a speed 5 m/s in opposite direction. The velocity ofthe second body after the collision is |
| Answer» ANSWER :D | |
| 13024. |
A rocket is moving at a speed of 200m/stowards a stationary target. While moving, it emits a wave of frequency 1000Hz. Calculate the frequency of the sound as detected by the target. (Velocity of sound in air is 330m/s ) |
|
Answer» Solution :The target is the source (as it is the source of echo) and the rocket's detector if the observer who INTERCEPTS the echo of FREQUENCY v'. Hence the frequency of the echo as detected by a detector attached to the rocket is `v''=(v+v_(0))/(v-v_(s))XXV=(330+200)/(330-0)xx2538.5` `=(530)/(330)xx2538.5` `~~4077Hz`. |
|
| 13025. |
The force F acting on a body moving in a circular path depends on mass of the body (m) velocity(v) and radius (r) of the circular path. Obtain the expression for the force by dimensional analysis method (k=1) |
|
Answer» SOLUTION :The PRINCIPLE of homogeneity of DIMENSIONS states that the dimensions of all the termsin a physical expression should be the same. For example, in the physical expression `v^2= u^2 + 2as` , the dimensions of `v^2 , u^2` and 2 as are the same and equal to `[L^2 T^(-2) ]` ` F prop m^a v^b R^c` `F = K m^z v^b r^c `K = 1 ` F= m^a v^b r^c` Dimensionally `[MLT^(-2) ] = [M]^a [LT^(-1) ]^b [L]^c` Campare the power of M,L and T a = 1...(1) b + c= 1....(2) - b= - 2 b = 2....(3) sub (3) and (2) we get b+c=1 2 + c = 1 c = -1.....(4) Substitute a, b and c value in force equation `F = m^a v^b r^c` ` = mv^2 r^(-1)` `F = (mv^2)/(r )` This equation is known as centripetal force. |
|
| 13026. |
To a car driver moving at 40 km*h^(-1) towards south, windappears to blow towards east. When the speed to the car is reduced to 20 km*h^(-1) wind appears to blow fromnorth -west . Findthe magnitude and direction of the actual velocity of the wind. |
|
Answer» SOLUTION :LET us choose : x-axisalong east and y-axis along north. Initial velocity of the car , `vecu_1 =-40 HATJ km*h^(-1)` Final velocity of the car , `vecu_2=-20hatjkm*h^(-1)` Let , `vecv` = actual velocity of the wind. Then , relative velocity of the wind respect to the car, `vecw=vecv-vecu or, vecv=vecu+vecw` Initially, `vecw_1=w_1hati, so vecv=vecu_1+vecw_1=w_1hati-40hatj .... (1)` Finally , `vecw_2=w_2 cos 45^@ HATI-w_2 sin 45^@ hatj` (as it is towards south -east) `=(w_2)/(sqrt(2))hati-(w_2)/(sqrt(2))hatj` `therefore vecv=vecu_2+vecw_2=(vecw_2)/(sqrt(2))hati-((w_2)/(sqrt(2))+20)hatj ..... (2)` Comparing the coefficients of `hatj` in (1) and (2) , `(w^2)/sqrt(2)+20=40 or, (w_2)/sqrt(2) =20` Then from (2) , `vecv=20 hati -(20+20)hatj=(20hati-40hatj) km *h^(-1)` (between east and south ) `therefore` Manitude of `vecv=v=sqrt((20)^2+(40)^2)=20sqrt(1+4)= 20 sqrt(5) km*h^(-1)` If `vecv` is inclined at anangle `THETA` with east,then `tan theta =(-40)/(20)=-2=tan(-63.4^@) or, theta =-63.4^@` So, the wind velocity is at anangle of `63.4^@` south of east. |
|
| 13027. |
A lift is coming from 8th floor and it just a about to reach 4th flor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct ? |
|
Answer» `x lt 0, V lt 0, a gt0` As the lift is coming in downward directions displacement will be negative. We have to see whether the MOTION is accelerating or RETARDING. We know that due to downward motion displacement will be negative. When the lift reaches 4th floor it is about to stop hence, motion is retarding in nature hence, `x lt 0, a gt 0.` As displacement is in negative direaction, velocity will also be negative i.e., `v lt 0.` THis can be SHOWN on the ADJACENT graph. 
|
|
| 13028. |
If water falls from a dam intoa turbine wheel 19.6m below ,the velocity of the water at the turbine is |
|
Answer» 9.8m/s |
|
| 13029. |
The efficiency of a Carnot engine operating between temperatures 27^@C and -123^@C is |
| Answer» ANSWER :A | |
| 13030. |
If the unit of mass is alpha kg, the unit of length is beta metre and the unit of time is "gamma' second, The magnitude of calorie in the new system is (1 Cal = 4.23) |
|
Answer» `4.2 alpha^2 beta^2 gamma^2` NEW units |
|
| 13031. |
A force of 1N acts on a 1 kg mass at rest for 1s. In another case 1N force acts on 1kg mass at rest and moves it through 1m. The ratio of kinetic energies in the two cases is |
| Answer» ANSWER :B | |
| 13032. |
The diameter of a circle is 2.486 m . Calculate its area with due regard to significant figures |
| Answer» SOLUTION :4.855 m^2 | |
| 13033. |
Vector representation of angular momentum (vecL) is |
|
Answer» `vecL=vecxxvecr` |
|
| 13034. |
A green length is incident from the water to the air- water interface at the critical angle (theta). Select the correct statement. |
|
Answer» The entire spectrum of VISIBLE LIGHT will come out of the water at an angle of `90^@` to the normal |
|
| 13035. |
A hollow sphere of mass 100g released from the top of an inclined plane inclination phi(=45^(@)) and height h(=8m). The coefficient of friction between the plane and the sphere is 0.25. The work doen (in J) by the force of friction as the sphere rolls down the inclined plane. |
|
Answer» |
|
| 13036. |
The kinetic energy k of a panicle moving along circle of radius R depends on the distance covered s as k = as^(2) where is a positive constant. The total force acting on the particle is |
|
Answer» `2A(s^(2))/(R)` |
|
| 13037. |
A bullet of mass 100 g is fired by a gun of 10 kgwith a speed of 2000 m/sfind recoil velocity of gun |
|
Answer» Solution :Accordingtoconservationof linearmomentum `mv+ mv =-0` Recoilvelocity `V= (-mv)/( M ) = (0.1 XX 2000)/(10)` `v= -20 m//s` |
|
| 13038. |
The mass of a space ship is 1000 kg. It is to be launched from Earth's surface out into free space the value of g and R (radius of Earth) are10 ms^(2)and 6400 km respectively. The required energy for this work will be. |
|
Answer» Solution :Potential ENERGY`U = - mgR_(e ) +mgh` (The FIRST term is independent of the height, so it can betakento zero ) `W = U= mgh"" p[ h approxR]` ` = 1000 xx 10 xx 6400 xx10^(3) = 64 xx10^(9)` `W = 6.4 xx10^(10) J ` |
|
| 13039. |
(A) IF the angles of the base of the prism are equal, then in the position of minimum deviation, the refracted ray will pass parallel to the base of prism. (R ) In the case of minimum deviation, the angle of incidence is equal to the angle of emergence. |
|
Answer» Both A and R are true and R is the correct explanation of A |
|
| 13040. |
What is the principle that sets limitations on the collapse of a white dwarf ? |
| Answer» SOLUTION :CHANDRA SEKHAR LIMIT. | |
| 13041. |
Draw plots for initial phase phi=0 for different periods. |
|
Answer» Solution :In `x(t) = A sin (OMEGA t+phi), phi =0` `x(t)= A sin omega t` Following graphs shows DISPLACEMENT VERSUS time for different periods.  In this plot the curves (b) has half the period and twice the FREQUENCY of the curve (a). |
|
| 13042. |
Two particles of mass m and M initially at rest at infinite distance. Find their relative velocity of approach due to gravitational force of attraction when their separation is a at any instant |
|
Answer» `SQRT((2G(M +m))/(a))` |
|
| 13043. |
The length , breadth , and thickness of a sheet are respectively 4.234 m , 1.005 m, and 2.01 cmfind the area and the volume of the sheet to correct number of significant figure |
| Answer» SOLUTION :8.72 m^2, 0.0855 m^3 | |
| 13044. |
Two friends A and B (each weighing 40 kg) are sitting on a frictionless platform some distance d apart. A rolls aball of mass 4kg on the platform towards B which B catches. Then B rolls the ball has a fixed speed of 5 m/s on the platform. |
|
Answer» speed of A after he catches the ball for the FIRST time is `(10)/(11)m//s` |
|
| 13045. |
Two bodies of different masses are dropped simultaneously from the top of a tower. If air resistance is same on both of them |
|
Answer» the HEAVIER body reaches the GROUND earlier |
|
| 13046. |
Two bodies of different masses are dropped similtaneously from the top of a tower .If air resistance is proportional to the mass of the body. |
|
Answer» the HEAVIER BODY REACHES the GROUND earlier |
|
| 13047. |
When a metal rod is heated it expands because |
|
Answer» the size of it atom increases |
|
| 13048. |
The internal energy U is a unique function of any thermal state, because change in U |
|
Answer» Does not DEPEND UPON path |
|
| 13049. |
During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its temperature. The ratio of (C_(P))/(C_(V)) for the gas is |
|
Answer» `(5)/(3)` `PT^(-3)` = constant …(i) For an adiabatic process, `PT^(gamma//1-gamma)` = constant …(ii) Comparing (i) and (ii), we get `(gamma)/(1-gamma) = -3` or `gamma = -3 + 3gamma` or `-2gamma = -3` or `gamma = (3)/(2)` As `gamma = (C_(P))/(C_(V)) :. (C_(P))/(C_(V)) = (3)/(2)` |
|
| 13050. |
A horizontal glass tube, sealed at both ends contains a column of mercury of length 10 cm at its middle. The two ends of the tube contain air at a pressure of 76 cmHg. IF the tube is held in a vertical position what will be the shift of the mercury column? Length of the capillary tube=100 cm. |
|
Answer» |
|