InterviewSolution
Saved Bookmarks
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.
| 1951. |
In refracting telescope, focal length of eyepiece is ……………than objective lens. |
|
Answer» |
|
| 1952. |
We can see a rainbow on a suuny day by looking at the sky through a water fountain. Why ? |
| Answer» SOLUTION :The RAINBOW is seen on ACCOUNT of DISPERSION of sunlight through water droplets of the FOUNTAIN. For details. | |
| 1953. |
Why does a current-carrying conductor experience a force in a magnetic field? |
| Answer» Solution :An electric CURRENTFLOWING through a conductor producesa magnetic field. As per Newton.s third LAW of motion, the magnet must also exert an equal and oppositeforce on the current-carrying conductor. THUS a current-carrying conductor experiences a FORCE in a magnetic field. In 1820, French Scientist Andre Marie Ampere experimentally demonstrated the existence of this force. | |
| 1955. |
What is electric energy? What is its commercial (or practical) unit? Define it. |
|
Answer» Solution : "Electric energy is the amount of energy consumed in an electric circuit in a given time t." The energy consumed not only depends UPON the electric power of the appliance but also upon the time for which the power is maintained. If a power P (watt) is maintained for time t (second), then the work DONE or electric energy consumed is  But the unit .watt. is very small. Therefore in actual practice we use a much larger unit called .kilowatt. which is equal to 1000 watt. Since electrical energy is the product of power and time, the unit of electric energy is, therefore, watt HOUR (Wh). "One watt hour is the energy consumed when 1 watt power is used for 1 hour." The commercial (or practical) unit of electric energy is kilowatt hour (kWh), commonly known as .unit.. 1 kWh = 1 kilowatt `xx` 1 hour = 1000 watt `xx` 3600 second `=3.6 xx 10^6` watt second `=3.6 xx 10^6` JOULE (J) Note: The unit kWh is equal to the electric I energy consumed, when electric power of 1 kW is consumed for 1 hour. [If 10 electric bulbs, each of rating 100W are used for 1 hour, then 1 unit of electric energy is consumed.] |
|
| 1956. |
Identily A. B, C, and D from the following nuclear reactions. (i) ""_(13)Al^(27)+ A to ""_(15)P^(30)+ B (ii) ""_(12)mg^(24)+ B to ""_(11)Na^(24)+ C (iii) ""_(92)U^(238)+ B to ""_(93)Np^(239)+ D |
|
Answer» Solution :(i) `""_(13)Al^(27)+""_(2)He^(4)to ""_(15)P^(30)+ ""_(0)n^(1)` (ii) `""_(12)mg^(24)+ ""_(0)n^(1) to ""_(11)Na^(24)+ ""_(1)H^(1)` (iii) `""_(92)U^(238)+ ""_(0)n^(1) to ""_(93)Np^(239)+ ""_(-1)e^(0)` A is alpha particle, B is neutron, C is proton and D is electron. |
|
| 1957. |
Conventionally, the direction of the current is taken as |
|
Answer» the DIRECTION of FLOW of NEGATIVE charge |
|
| 1958. |
How will you explain following statements with the help of the anomalous behaviour of water? In cold regions in winter the pipes for water supply break and even rocks crack. |
|
Answer» Solution :(i) During winter SEASON, in COLD countries the temperature of atmosphere falls well below `0^(@)C`. (ii) If water is present within the crevices of the rocks, then due to its ANOMALOUS behaviour, water begins to expand below `4^(@)C`. (iii) As there is no place in the crevices for the expansion of water, it exerts tremendous pressure on the rocks which results in the crumbling of the rocks. (iv) Hence, sometimes rocks crumble into pieces in cold countries during winter. |
|
| 1959. |
How is a voltmeter connected in a circuit to measure the potential difference between two points ? |
| Answer» SOLUTION :A VOLTMETER is always CONNECTED in parallel to the circuit ACROSS those two points, potential difference between which is to be measured. | |
| 1960. |
State the two factors that constitue the environment. |
| Answer» SOLUTION :The two factors that CONSTITUTE the ENVIRONMENT are biotic and ABIOTIC factors. | |
| 1961. |
How do we get a spectrum of seven colors ? |
|
Answer» Solution :1. When white light is incident on a PRIM, different colours bend through different angles . 2. Among the seven colours red bends the least while violet bends the most. 3. The seven colours EMERGES along different paths and GET SEPARATED and we get a SPECTRUM of seven colour. |
|
| 1962. |
Higher the temperature of air, lower is the amount of water vapour needed to saturate it. |
|
Answer» SOLUTION :False. HIGHER the temperature of air, higher is the amount of WATER vapour NEEDED to SATURATE it. |
|
| 1963. |
What is energy pyramid ? |
|
Answer» Solution :a. An energy pyramid graphically represnts the flow of energy at each trophic level in an ECOSYSTEM. b. The sequence of flow of energy from bottom to top in an energy pyramid occurs in the FOLLOWING manner `:` Producers `rarr` Primary consumers `rarr` Secondary consumers `rarr` Tertiary `//` APEX consumers. c. In an energy pyramid, the energy decreases as we move from the bottom to the top. d. Only 10% of energy is transferred to next level in an energy pyramid . The remaining 90% is LOST in the form of heat. |
|
| 1964. |
What are the limitations of extracting energyfrom (i) the wind (ii) waves (iii) tides |
|
Answer» Solution :(i) (a) It is not AVAILABLE at all times. (b)It REQUIRES a very large area of land. (c) It is not POSSIBLE to have a windmill everywhere as to run it , the minimum wind speed of 15 km/hr is required (only possible in open areas like the seaside) (ii) (a) Wave energy would be viable proposition only where waves are very STRONG. (b) It is costly to set up devices to trap wave energy. (iii) (a) Very few sea coasts in the world have suitable sites for the purpose of harnessing tidal energy . (b) The rise and fall of tides happen only twice in a day and is not sufficient to generate ELECTRICITY continuously. |
|
| 1965. |
Pick out the chemically most reactive elements from the given triads. Li,Na,K and F,Cl,Br |
|
Answer» Li & F |
|
| 1967. |
Rahul got a bike on his 18th birthday from his parents. His father instructed him to always wear helmet while driving. He reluctantly obeys him but does not tie the straps of helmet properly. (i) According to you, what danger Rahul can face in future while he is driving his bike. (ii)Which vital organ/organs get protection by wearing the helmet while driving the twowheelers? (iii) What values are being neglected by Rahul? |
|
Answer» Solution :(i) He MAY get HEAD injury that may even PROVE FATAL to him. (ii) Brain, Eye. (iii) Obeying traffic rules while TRAVELLING on the roads, be careful while driving, obeying instructions by elders. |
|
| 1968. |
Find the moment of inertia of a disc of radius R and mass m about an axis in its plane at a distance R/2 from its centre |
| Answer» SOLUTION :`1/2 MR^(2)` | |
| 1970. |
Refractive index of water with respect to air is 1.33. What is the refractive index of air with respect to water ? |
| Answer» SOLUTION :`n_(AW) = (1)/(n_(WA)) = (1)/(1.33) = 0.75` | |
| 1971. |
Explain theunderlying principle andworkingof an electric generatorby drawing a labelled diagram. Whatis the function of the brushes ? |
|
Answer» Solution :PRINCIPLE : SEE answer to Q.46 of Question and Answer section . Labelled diagram and working: see answerto Q.47 ofQuestion and Answer section . The function of thebrushes in an ELECTRICGENERATOR : Brushes are used to transmit currentinduced externally from coil ABCD to the external CIRCUIT. |
|
| 1972. |
Placenta : |
| Answer» SOLUTION :SUPPLYING NOURISHMENT to the GROWING FOETUS. | |
| 1973. |
Shekhar was observed a bulb and asked some questions to you. Those are What is the material of the filament ? |
| Answer» SOLUTION :The MATERIAL of the FILAMENT in the BULB is TUNGSTEN. | |
| 1974. |
Whilea magnet is movedtowards a coil , will the induced currentdecrease or increase ? Why ? |
| Answer» SOLUTION :INCREASES , because the NUMBEROF MAGNETICFIELDLINES LINKED with the coilincreases . | |
| 1975. |
Suresh standing symmetrically between two cliffs claps his hands and starts hearing a series of echoes at intervals of 1 second. If speed of sound in air is 340 m/s, the distance between the parallel cliffs must be |
|
Answer» 320 m |
|
| 1976. |
Classify the colours green, red, indigo and yellow in the descendinğ order of their wavelengths. |
|
Answer» |
|
| 1977. |
Which options show the correct direction of current ? |
|
Answer»
|
|
| 1978. |
The major problem In harnessing nuclear energy is how to |
|
Answer» split nuclel |
|
| 1979. |
When does (i) height attained by a projectile maximum? (ii) horizontal range is maximum? |
|
Answer» SOLUTION :HEIGHT is MAXIMUM at `theta = 90` Range is maximum at `theta = 45.` |
|
| 1980. |
On which part images are formed in human eye ? |
|
Answer» Cornea |
|
| 1981. |
A personis not able to see for off objects clearly. From which defect of the eye the person is suffering ? How to correct this defect ? |
|
Answer» Solution :The person is suffering from myopia or short sightedness. Myopia or short-sightedness. In normal eye, the FAR point is at INFINITY. The rays coming from distant object (at infinity) gets focussed on retina. In turn, the retina conveys the massage to BRAIN via optical nerve. Causesof Defect in Defective Eye. The defect arise due to EITHER : (i) the length of eye ball is elongated (becomes longer than normal) (ii) the focal lengthof eye lens has decreased. Due to either or both the causes, the eye is not able to focus the rays from distant object are retinal . Focussing is thereat a point O in FRONT of retina . Image formed on retina is , blurred. The defective eye is however able to focus the object upto its far point . Correction of Defect We have observed that the defective eye has not been able to focus less inclined rays but has been able to focus more inclined rays. To correct this defect, a concave or a divergent lens of appropriate focal length is placed in front of the eye so that parallel rays coming from infinity appear, afterrefraction through the lens , to come from the far point when eye isunaccommodated. Theseparallel rays from a distant object shall be brought to focus upon the retina. Obviously, the focal length of such a lens is equal to the distance of the far point from the eye . 
|
|
| 1982. |
List the uses of concave mirror ? |
|
Answer» Solution :● Shaving mirror ● Reflector in automobile light and torches. ● By dentists to SEE back side of tooth. ● Reflector of SOLAR furnaces. |
|
| 1983. |
If, the current I, through a resistor is increased by 100.% (assume that the temperature of the resistor remains unchanged), find the percentage increase in power dissipated. |
|
Answer» <P> Solution :Power dissipated `P = I^2 R`Current after increased by 100 % = I. `=I + (100I)/100` `=2I` So, new power `P. = I.^2R =(2I)^2R =4l^2R` `:.` PERCENTAGE increase in power dissipation `=(p. -p)/p xx 100%` `=(4l^2 R -I^2R)/(I^2R) xx 100%` `=(I^2R (4-1))/(I^2R) xx 100%` `=3xx 100%` `=300%` |
|
| 1985. |
Compare the power used in the 2Omega resistor in each of the following circuits: i] a 6 V battery in series with 1Omegaand2Omega resistors, and ii] a 4 V battery in parallel with 12Omegaand2Omega resistors. |
|
Answer» Solution :i] Potential difference M = 6 V Here `1Omegaand2Omega` resistors are connected in series, `therefore` equivalent resistance of the circuit [R] = 1 + 2 = `3Omega`, According to Ohm.s law `V=IRorI=V/R=6/3=2A` the CURRENT through the circuit [I] = 2A Now the power USED in the `2Omega` resistor Power = `I^(2)R=2xx2xx2=8W` ii] Potential difference, V = 4V `12Omegaand2Omega` resistors are connected in PARALLEL. The voltage across each component of a parallel circuit REMAINS the same. Hence, the voltage across `2Omega` resistor will be 4 V. Power consumed by `2Omega` resistor is given by `P=V^(2)/R=4^(2)/2=8W` `therefore` the power used by `2Omega` resistor is 8W. |
|
| 1986. |
Arabari forests of Bengal is dominated by |
|
Answer» teak |
|
| 1987. |
State whether the following statements are true or false by writing T/F against them. (a) Earth moves around Sun with a uniform velocity. (b) The motion of moon around Earth in a circular path is an accelerated motion. ( c) A uniform linear motion is unaccelerated, while a uniform circular motion is an accelerated motion. (d) In a uniform circular motion, the speed continuously changes because the direction of motion changes. (e) A boy experiences a centrifugal force on his hand when he rotates a piece of stone tied at one end of a string. holding the other end in the hand. |
| Answer» SOLUTION :(a) F (B) T (C ) T (d ) F (E ) F | |
| 1988. |
A spherical mirror produces an image of manification -1 on a screen placed at distance of 50 cm from the mirror. (i) Write the type of mirror. (ii) Find the distance of theimage from the object. (iii) What is the focal length of the mirror? (iv) Draw the ray diagram to show the image formation in this case. |
|
Answer» Solution :(i) As magnification is negative, the IMAGE formed is real. Hence it is a CONCAVE mirror. (II) `m=-v//u=-1` `u=-v=-50cm` Distance of the image FORM the object `v-u=-50-(-50)=0cm` (ii) By using mirror formula. `1//f=1//v+1//u` `=1//(-50)+1//(-50)=-1//25` `f=-25cm` 
|
|
| 1989. |
Which hormone is seereted during emergency situation in man? |
|
Answer» Solution : (a) Hormone AUXIN INDUCES parthenocarpy. (B) Epinephrine and NOREPINEPHRINE are secreted during emergency SITUATION in man |
|
| 1990. |
Electric dipole moment is |
|
Answer» scaler |
|
| 1991. |
The headquarter of the National Disaster Response Force is located in ............. . |
|
Answer» |
|
| 1992. |
What is the function of an earth wire? Why is it necessary to earth metallic appliances ? |
| Answer» Solution :The metallic body of electric appliances is connected to the EARTH by MEANS of earth wire so that any leakage of electric CURRENT is TRANSFERRED to the ground. This prevents any electric shock to the user. | |
| 1993. |
Heparin is produced by : |
|
Answer» leech |
|
| 1994. |
Hight earth orbits and low earth orbits. |
Answer» SOLUTION :
|
|
| 1996. |
We feel that some objects are cold, and some are hot. ls this feeling related in some way to our body temperature? |
|
Answer» Solution :1.Yes, this feeling is related in some way to our body temperature. 2. We FEEL some OBJECTS as COLD, if their temperature is less than our body temperature. 3. We feel some objects as hot, if their temperature is more than our body temperature. |
|
| 1997. |
When a ray of light travelling parallel to the principal axis of a concave mirror strikes at the polished surface of mirror, the reflected ray |
|
Answer» is sent BACK along the same direction |
|
| 1998. |
List two observations which you make when you add a pinch of sodium hydrogen carbonate to acetic acid in a test tube. Write chemical equation for the reaction that occurs . |
|
Answer» Solution :TWO observations: (a)Brisk EFFERVESCENCE (b) Evolution of a colourless/odourless GAS. `CH_(3)COOH+NaHCO_(3)toCH_(3)COONa+H_(2)O+CO_(2)` |
|
| 1999. |
Define angle of deviation. Why do different components of white light split up into spectrum when it passes through a triangular glass prism? Show the angle of deviation for red colour when white light passes through a prism. |
|
Answer» SOLUTION :The angle between the EXTENDED incident ray and the emergent ray is called the angle of deviation. This is because the DIFFERENT colours travel through a glass prism at different speeds. For DIAGRAM. |
|
| 2000. |
The iron door of a building is 3m broad. It can be opened by applying a force of 100N normally at the middle of the door. Calculate (a) the torque needed to open the door, (b) the least force and its point of application to open the door. |
|
Answer» Solution :(a) Given F=100N distance of point of application of force `r=1/2 times` BREADTH of door `=1/2 times 3m=1.5 m` Moment of force (torque) NEEDED to open the door `= F times r=100N times 1.5 m=150 Nm`…….(i) (b) The force required will be least if it is applied at the farthest point from the HINGES. Therefore the force should be applied at the FREE end of the door i.e at a distance of 3m from the hinges. Let the force required be F. newton , then Moment of force =`F. times 3N m` From eqns. (i) and (ii) `F. times 3=150` `therefore F.=150/3=50N` |
|
