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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.
| 701. |
Calculate the pressure exerted by a column of water of height 0.85m (density of water, rho_(w) = 1000 kg m^(-3)) and kerosene of same height (density of kerosene, rho_(k) = 800kg m^(-3)) |
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Answer» Solution :PRESSURE due to water= `h rho_(w) g = 0.85 m XX 1000kgm^(-3) xx 10 m s^(-2) = 8500`Pa. Pressure due to kerosence = `h rho_(k) g = 0.85 m xx 800kgm^(-3) xx 10 MS^(-2) = 6800` Pa . |
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| 702. |
A body will experience minimum upthrust when it is completely immersed in |
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Answer» turpentine |
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| 703. |
A car initially at rest starts moving with a constant acceleration of 0.5 m s^(-2) and travels a distance of 25 m. Find : (i) its final velocity and (ii) the time taken. |
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Answer» Solution :Given initial velocity u =0 acceleration a= 0.5 m `s^(-2)` Distance TRAVELLED S = 25 m. (i) From equation of motion `v^(2) = u^(2)+2AS` `v^(2) = (0)^(2) +2 xx0.5xx25` or `v^(2) =25` or Final velocity v = `SQRT(25) = 5 m s^(-1)` (ii) From equation of motion v = u + at 5 =0 +0.5 `xx`tor 0.5 t =5 `:.` TIME taken t `= (5)/(0.5)` = 10 s. |
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| 704. |
An object performing uniform circular motion performs accelerated motion. |
| Answer» Solution :Magnitude of velocity (speed) of an OBJECT performing uniform CIRCULAR motion is maintained constant, but the direction of velocity is in the direction of tangent DRAWN at each POINT on circular path, i.e., is different. So velocity (vector QUANTITY) also changes continuously. Hence, the object performs accelerated motion. | |
| 705. |
A body of weight 800 N sinks in a liquid. The weightof the liquid displaced is 200 N What will be the weight of the body in liquid? |
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| 706. |
If an object is falling freely from certain height towards the surface of earth, its total mechanical enrgy …………… |
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Answer» decreases = Potential energy `E_(p) +` Kinetic energy `E_(K)` The decreases in potential energy of a free FALLING OBJECT is equal to increases in kinetic energy. |
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| 707. |
A train takes 2 h to reach station B from station A, and then 3 h to return from station B to station A. The distance between the two stations is 200 km. Find : (i) the average speed, (ii) the average velocity of the train. |
| Answer» Solution :(i) 80 `KM H^(-1) ` (ii) zero | |
| 708. |
A car of 1000kg moves with a velocity 20m//s. On applying brakes it comes to rest in 5s. What is the initial momentum? |
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Answer» =`1000xx20` = `20000KG m/s` |
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| 709. |
Drill a hole at the bottom of an open bottle and fill itwith water. Water goes out through the hole. Thenallow the bottle to fall freely. What do you observe? |
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| 710. |
Find out the reasons A running elephant cannot change its direction suddenly. |
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| 711. |
Can you hear the sound produced due to vibrations of a seconds' pendulum ? Give reason. |
| Answer» Solution :No. Reason: The FREQUENCY of SOUND produced due to vibrations of seconds. PENDULUM is 0.5 Hz which is INFRASONIC sound. | |
| 712. |
Is the radius of the earth the same everywhere? |
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| 713. |
What is the relation between the period of rotation (R_(T)) and periond of revolution (R_(V)) of moon? |
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Answer» `R_(T) = R_(V)` |
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| 714. |
A particle covers equal distances in same direction on a linear path with different velocities v _(1) , v_(2) and v _(3)find the formula for its average speed. |
| Answer» SOLUTION :Average SPEED `= ( 3 v _(1) v _(2) v _(3)) .( v _(1) v _(2)+ v _(3) + v _(2) v _(3))` | |
| 715. |
One of the following can hear infrasound. This one is: |
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Answer» dog |
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| 716. |
Calculate the mass of air in a room of dimensions 4.5 m x 3.5 m x 2.5 m if the density of air at N.T.P. is 1.3 "kgm"^(-3) |
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| 717. |
When a screw gauge of least count 0.01 mm is used to measure the diameter of a wire, the reading on the sleeve is found to be 1 mm and the reading on the thimble is found to be 27 divisions.If the zero error + 0.005 cm, what is the correct diameter ? |
| Answer» SOLUTION :0.122 CM | |
| 718. |
When a screw gauge of least count 0.01 mm is used to measure the diameter of a wire, the reading on the sleeve is found to be 1 mm and the reading on the thimble is found to be 27 divisions.What is the diameter of the wire in cm ? |
| Answer» SOLUTION :0.127 CM | |
| 719. |
A particle starts to move in a straight line from a point with velocity 10 m s^(-1) and acceleration - 2.0 m s^(-2). Find the position and velocity of the particle at (i) t = 5 s, (ii) t' = 10 s. |
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Answer» Solution :Given u =10 m `s^(-1) ` a = 2.0 `m s^(-1)` (i) Displacement at t = 5 s is `S = ut +(1)/(2) a t^(2)` `= 10 XX5 +(1)/(2) xx(-2.0) xx(5)^(2)` = 50 -25 =25 m i.e., after 5 s the PARTICLE will be at distance 25 m from the starting point. VELOCITY at t = 5 s is v = u +a t or v = 10 + (-2.0) `xx` 5=0 i.e., the particle is momentarily at rest at t = 5 s. (ii) Diplacement at t = 10 s is `S= ut +(1)/(2) a t^(2)` `= 10 xx10 +(1)/(2) xx(-2.0) xx(10)^(2)` =100- 100 =0 (zero ) i.e., after 10 s the particle has come BACK to the starting point Velocity at t = 10 s is v = u + at or v = 10 + `(-2.0 ) xx 10 = -10 m s^(-1)`. i.,e., velocity is 10 `m s^(-1)` towards the starting point (i.e., opposite to the initial direction of motion ). |
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| 720. |
An experiment is conducted to determine the velocity of sound by resonating air column method where the first and second resonating lengths are 20 cm and 60 cm , respectively , for a tuning fork of frequency 100 Hz. Arrange the following steps in a sequential order to determine the velocity of sound . (A) Note the frequency of the tuning fork (n) that is used to produce resonance in the closed organ tube . (B) This will be the fundamental frequency of air column . (C) The velocity of sound in air , v = 2n (l_(2) - l_(1)). (D) Identify the first and second resonating lengths when the tuning fork of frequency (n) is used from the given information . Let it be l_(1) and l_(2). respectively. |
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Answer» ABDC |
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| 722. |
Distinguish between conduction, convection, and rediation. |
Answer» SOLUTION :
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| 724. |
Two hockey players of opposite teams, while trying to hit a hockey ball on the ground collide and immediately become entangled. One has a mass of 60 kg and was moving with a velocity 5.0 m s^(-1) while the other has a mass of 55 kg and was moving faster with a velocity 6.0 m s^(-1) towards the first player. In which direction and with what velocity will they move after they become entangled ? Assume that the frictional force acting between the feet of the two players and ground is negligible. |
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Answer» Solution :Let the first player be moving from left to right. By CONVENTION left ot rightis taken as the positivedirection and thus right to left is th E negative direction. If symbols m and u represent the mass and initial velocity of the two players, respectively. Subscripts 1 and 2 in these physical quantities refer to teh two hockey players Thus, `m_(1) = 60 kg , u_(1) = + 5 ms^(-1), and m_(2) = 55 kg` `u_(2) = - 6 ms^(-1)` The total momentum of the two players before the collision = 60 kg ` xx ( + 5 ms^(-1)) + 55 kg xx (- 6 ms^(-1))` ` = -30 kg ms^(-1)` If v is the velocity of the two entangled players after the collision, the total momentum then ` = (m_(1) + m_(2)) xx v` ` = (60+ 55) kg xx v ms^(-1)` ` = 115 xx v kg ms^(-1)`   Equating the momenta of the system before and after collision, in ACCORDANCE with the law of conservation of momentum, we get ` v = - (30)/(115)` ` = -0.25ms^(-1)` Thus, the two entangled players would move with velocity 0.26 m `s^(-1)` from right to left, that is in the direction the second player was moving before the collision. |
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| 725. |
A person takes observations from odometer of his own motorcar while starting journey as well as after 40 min of his journey, which are found as 1046 km and 1096 km respectively. What would be the average speed of the motorcar? |
| Answer» SOLUTION :`75 KM H ^(-1)` | |
| 727. |
The ratio of load to displacementof the rider from its zero mark in a Roman steel yard is 20 gf:1 cm. If therider isdisplaced by 20 cm from its zero mark, the load attached to the steel yard is ________. |
| Answer» Answer :C | |
| 728. |
Define conduction band. |
| Answer» Solution :The process of transfer of HEAT in solids from a region of HIGHER temperature to a region of lower temperature without the actual movement of MOLECULES is called CONDUCTION | |
| 729. |
There are two towns Ramgarh and Arjangarh which are separated by a hill. The people of one town have to travel on a zig-zag road which goes over the hill so as to reach the other town. Gaurav is a student of class IX in Ramgarh. Onnce Gaurav went from Ramgrah to Arjangarh on a scooter with his father. Driving at a constant speed of 50km/h on the hilly road, it took exactly 30 minute to reach Arjangarh. One day Gaura told his father that if a straight tunnel could be dug through the hill, then it would become very easy for the people of two towns to visit each other. keeping this is mind, Gaurav invited the people of both the towns and took a delegation to the Collector's office. This delegation demanded the construction of a straight tunnel road through the hill. Gaurav explained the various advantages of connecting Ramgarh and Arjangarh through a tunnel road in the hill. The collector liked the idea and a straight tunnel road was constructed after some time. One day Gaurav went from Ramgarh to Arjangarh through the straight tunnel road on the scooter with his father. Driving at a constant speed of 50 km/h,it took them just 12 minutes to reach Arjangarh. Both, Gaurav and his father were very happy. (a) What was the distance covered by Gaurav on going from Ramgarh to Arjangarh by travelling on road over the hill? (b) What is the distance covered by Gaurav on going from Ramgarh to Arjangarhby travelling on straight tunnel road/ (c) How much less distance is to be covered now in going through the tunnel than on going over the hill? (d) What is the displacement of Gaurav from Ramgarh on reaching Arjangarh? (e) State two advantages of construction of the tunnel road for the people of two towns. (f) What values are displayed by Gaurav in this episode? |
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Answer» SOLUTION :DISTANCE covered (over the hill) = Speed `xx` Time taken `= 50 xx (30)/(60km) (30 min = (30)/(60)h)` `= 25km` (B) Distance covered (on tunnel road) = Speed `xx` Time taken `=50 xx (12)/(60)km (12 min =(12)/(60)h)` `= 10 km` (c) Less distance covered `= 25 km - 10 km` `= 15km` (d) Displacement = 10 km (It is the shortest, straight line distance between the two towns) (e) (i) Saving of fuel (because now less fuel is consumed to travel only 10 km distance as compared to 25 km earlier) (II) Saving of time (because now less time is taken in travelling 10 km distance than 25km earlier) (f) The values displayed by Gaurav are (i) RESPONSIBLE citizen (ii) Knowledge of distance travelled and displacement (ii) Application of knowledge in real-life siutations (iv) Conservation of fuel, and (v) Saving people's time. |
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| 730. |
In an experiment, Anhad studies sound waves. He sets up a loundspeaker to produce sound as shown below: Anhad adjuts the signal to the loudspeaker to given a sound of frequency 200 Hz. (a) What happens to tha air in-between Anhad and the loudspeaker? (b) Explain how Anhad receives sound in both ears. |
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| 731. |
In 5 successive measurements, the values of period of oscillation of a simple pendulum are obtained as T_(1)=2.63,T_(2)=2.56,T_(3)=2.42,T_(4)=2.71 and T_(5)=2.80 (in s). Demonstarte the different errors and range of a measurement. |
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Answer» Solution :`T_("mean")=underset(f)(SUM)T_(i)//5=(2.63+2.56+2.42+2.71+2.80)//5` `=(13.12)/(5)=2.624` s [mean value of T] `|DeltaT_(i)|=|2.63,2.62|,|2.56-2.62|,|2.42-2.62|,|2.71-2.62| and |2.80-2.62|` `=0.01,0.06,0.20,0.09 and 0.18` (s) [ABSOLUTE errors] `DeltaT_("mean")=underset(i)(sum)|DeltaT_(i)|//5=(0.01+0.06+0.20+0.09+0.18)//5=0.54//5` `=0.11`s [mean absolute error] RANGE of a measurement `T_("mean")+-DeltaT_("mean")=2.62+-0.11s` Relative error`=DeltaT_("mean")//T_("mean")=(0.11)/(2.62)xx100=4%` |
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| 732. |
A body starts from rest with a uniform acceleration of 2 m s^(-1) . Find the distance covered by the body in 2 s. |
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| 733. |
Which force is behind capillary rise? |
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| 734. |
Mass and weight of a body is determined at the pole and at the equator Is there any change in the weight? |
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| 735. |
A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the so |
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| 736. |
The power of an electric iron is 1200 W. It is used daily for 30 minute. How much electrical energy would be consumed in April month of any year? |
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Answer» `t=30` minute = `0.5h` TOTAL ELECTRICAL energy, E = POWER `XX` TIME `xx` days in April month `=1.2xx0.5xx30` `=18kWh` |
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| 737. |
Which one of the following is not the unit of energy ? |
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Answer» JOULE |
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| 738. |
Assertion : Incident ray is directed towards the centre of curvature of spherical mirror. After reflection it retraces its path. Reason : Angle of incidence i = Angle of reflection r = 0°. |
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Answer» If both assertion and reason are TRUE and reason is the CORRECT explanation. |
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| 739. |
What does the path of an object look like when it is in uniform motion ? |
| Answer» SOLUTION :The PATH of the OBJECT is a STRAIGHT LINE. | |
| 740. |
Why are household appliances connected in parallel. |
| Answer» Solution :The home appliances are connected in parallel. This is because, when the appliances are connected in parallel, each of them can be switched on and off independently. This is a feature that is essential in a HOUSE WIRING. Also, if the appliances were wired in series, the POTENTIAL DIFFERENCE across each appliance WOULD vary depending on the resistance of the appliance. | |
| 741. |
____ is the number of vibrations in the medium in one second. |
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| 742. |
An empty cylindrical tank having diameter 5 m is filled with water through a hose pipe having radius 25 cm. If pressure at the bottom of the container increases at a rate of 10^(3)"Pa s"^(-1), calculate the speed of water flowing through the hose pipe. ("Take g 10 m s"^(-2)) |
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Answer» Solution :`P=h_(1)dg` DETERMINE the height 'h' of the liquid COLUMN. Volume of water collected = Volume of water flowing through the pipe. `pir_(1)^(2)h_(1)=pir_(2)^(2)h_(2)` Where `r_(1)andr_(2)` are the radius of cross section of the container and the pipe, respectively. |
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| 743. |
The sound of an explosion on the surface of a lake is heard by a boat man 100 m away and by a diver 100 m below the point of explosion. (i) Who would hear the sound first : boat man or diver? (ii) Give a reason for your answer in part (1). (iii) If sound takes time to reach the boat man, how much time approximately does it take to reach the diver? |
| Answer» Solution :(i) diver (II) SOUND TRAVELS faster in waterthan in air(III) 0.25 t. | |
| 744. |
What isheat? |
| Answer» Solution :The sum of the KINETIC and POTENTIAL ENERGY is CALLED the internal heat energy of the molecules This internal energy when FLOWS out is called heat energy. | |
| 746. |
When two balls, one of iron and the other of aluminium, are completely immersed in strong salty water they undergo an equal loss in weight. This shows that iron and aluminium balls have: |
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Answer» the same densities |
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| 747. |
Certain force acting on a 20 kg mass changes its velocity from 5ms^(-1) to 2ms^(-1). Calculate the work done by the force. |
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Answer» The work DONE by the force = change in kinetic ENERGY = Final `E_(k)` - Initial `E_(k)` `=(1)/(2)MV^(2)-(1)/(2)m u^(2)` `=(1)/(2)m(v^(2)-u^(2))` `=(1)/(2)m(v^(2)-u^(2))` `=(1)/(2)xx20xx[(2)^(2)-(5)^(2)]` `=10xx(4-25)=10xx(-21)=-210J` |
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| 749. |
Complete the following sentences. (a) The acceleration of the body that moves with a uniform velocity will be ____ (b)A train travels from A to station B with a velocity of 100 km/h and returns from station B to station A with a velocity of 80 km/h. Its average velocity during the whole journey in ____ and its average speed is ______ |
| Answer» SOLUTION :(a) CONSTANT ,(B) ZERO, 90 km/h | |
| 750. |
The relative densities of four liquids P,Q,R and S are 1.26,1.0,0.84, and 13.6 respectively .An object is floated in all these liquids ,one by one .In which liquid will is maximum volume submerged under the liquid ? |
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Answer» P |
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