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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.
| 4001. |
Describe a solar cooker. Give its adavantages. |
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Answer» Solution :Solar cooker is a device used for cooking food with the help of solar energy. A solar cooker consists of an insulated metal box which is painted all black from inside. A plane mirror reflector is attached to the box. There is a thick glass sheet which acts as a cover over the box. The food to be cooked is placed in containers which are also painted black from outside. These containers are placed in the box and the box is covered with the glass sheet. The cooker is placed in sunlight and the position of the reflector is adjusted in such a way that a strong beam of sunlight falls over the cooker top. These rays pass through the transparent glass sheet and are absorbed by the black box and the containers. The use of black surface and black containers is due to the FACT that a black surface ABSORBS more heat than nay other colour. Therefore, the box and the containers absorb maximum amount of infra-red radiations from the sunlight falling on it. As a RESULT, the temperature inside the box rises to about `100^(@)-140^(@)C` in two to three hours and this heat cooks the food in the prepare food items which required slow heating and cannot be used for baking and frying purposes. Advantages of a solar Cooker The IMPORTANT advantages of a solar cooker are : (i) The use of solar cooker for cooking food materials saves fuel.  (II) It is a cheaper method of cooking food. (iii) It does not cause any pollution problems because this method of cooking does not give any smoke. (iv) In this method, food is cooked at comparatively lower temperature and therefore, the nutrients of food are not destroyed during cooking. |
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| 4002. |
Which of the following measurement is most precise? |
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Answer» `5.00mm` |
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| 4003. |
Draw a schematic diagram of an electric circuit comprising of 3 cells and an electric bulb, ammeter, plug-key in the ON mode and another with same components but with two bulbs in parallel and a volbneter across the combination. |
Answer» SOLUTION :
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| 4004. |
What are the important limitations of wind energ |
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Answer» SOLUTION :• Cost of maintaining WIND ENERGY is high • Wind energy farms can be established only at places where wind blows for greater part of year and SPEED is greater than 15KMPH. |
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| 4005. |
The radiations present in sunlight which make a solar cooker work are : |
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Answer» visible LIGHT rays |
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| 4006. |
Can a body be in equilibrium while in motion ? If yes, give an example. |
| Answer» Solution :Yes, if BODY has no linear and angular acceleration. Hence a body in UNIFORM straight LINE MOTION will be in equilibrium. | |
| 4007. |
An electric iron of 750W rating is used for 20hours. The amount fo electrical energy consumed is………units. |
| Answer» SOLUTION :15, `E=Pt=750/1000 KW TIMES 20h=15 kWh=15 UNITS` | |
| 4008. |
Theessential differencebetween and AC generatorand a DC generator is that….. |
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Answer» an AC generatorhas an electromagnet while a DC generator has permanet magnet. [DUETO theslip rings , the directionof the currentproducedby an AC generatoris REVERSED at regualarintervalof TIME , while the current produced by a DC generator always flows in one direction]. |
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| 4009. |
What are marginal rays ? A 4cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 24cm. the distance of the object from the lens is 16 cm find the position size and nature of the image formed using the lens formula. |
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Answer» Solution :The ray which stricks the mirror surface ncar the periphery are CALLED MARGINAL rays for comer lens. f = -24 CM. u= 16 cm using lens formula `(1)/(f)= (1)/(v) =(1)/(u)` `(1)/(24)= (1)/(v)- (1)/(-16)= (2-3)/(48)= (-1)/(48)` V= -48 now `h_(1)= 4 cm` so magnitication.`m= (h_(2))/(h_(1))= (v)/(u)` `h_(2)= (v)/(u) xx h_(1)= (-48)/(-16) xx 4= 12 cm` The image is formed at a distance of 48 cm from the optical focus of the lens on the same side of the object. This is indicated by the negative sign. Size of image is three times the size of objec i.e 12 cm. Nature of image: Positive sign in the image height INDICATES that image is virtual and erect. |
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| 4010. |
The beautiful phenomenon of the rainbow is a combination of different phenomena - dispersion, internal reflection and refrection of light. The rainbow appears in the sky after a rainfall. The water droplets act as small prisms. When sunlight enters the water droplets present in teh atmosphere, they refract and disperse the incident Sunlight. Then, they reflect internally inside the droplet and finally again refract it. As a collective effect of all the phenomena, the seven coloured rainbow is observed. Q. How do refraction and dispersion take place ? |
| Answer» Solution :When light rays of Sun enter the water DROPLETS of ATMOSPHERE, the refraction of light OCCURS as the medium changes from AIR to water. The direction of light rays also change and at the sametime, due to DECREASE in the velocity of light, the splitting of light rays result in dispersion. | |
| 4011. |
The beautiful phenomenon of the rainbow is a combination ofdispersion, internal reflection and refraction of light. The rainbow appears in the sky after a rainfall. The water droplets act as small prisms. When sunlight enters the water droplets present in the atmosphere, they refract and disperse the incident Sunlight. Then, they reflect internally inside the droplet and finally again refract it. As a collective effect of all the phenomena, the seven coloured rainbow is observed. Q. Which three major phenomena are responsible for rainbow ? |
| Answer» Solution :The three major PHENOMENA RESPONSIBLE for rainbow are dispersion, internal reflection and REFRACTION of SUNLIGHT. | |
| 4012. |
Out of the total solar energy striking the periphery of earth, what fraction reaches its surface? |
| Answer» SOLUTION :APPROXIMATELY HALF. | |
| 4013. |
Explain the underlying principle and working of an electric generator by drawing a labelled diagram, What is the function of brushes ? |
Answer» Solution :Principle : An electric generator works on the principle of ELECTROMAGNETIC induction PHENOMENON. According to it, whenever a coil is rotated between the poles of a magnet, an induced CURRENT is set up in the coil, whose DIRECTION is given by Fleming.s right hand rule.  Working : Let in the beginning as shown in fig brushes `B_(1) and B_(2)` respectively. Let the axle attached to the rings be rotated such that arm AB of the coil MOVES up and arm CD moves down in the magnetic field, Due to rotation in them. As per Fleming.s right hand rule induced currents in these arms are along the direction AB and CD. Thus an induced current flows along ABCD and current flows along ABCD and curren in the external circuit flows from `B_(2) "to" B_(1)`. After half a rotation, arm AB starts moving down and the arm CD upward Therefore, direction of induced current in these arms change. Thus net induced current now is in the direction DCBA. In the external circuit now current flows from `B_(1) "to" B_(2)`. Thus after everyhalf rotation current changes its direction and an alternating current is obtained from the generator. Function of Brushes : Brushes are kept pressed on two slip rings separately, outer ends of the brushes are connected to the galvanometer (or the external load) thus brushes help in transferring current from the coil ABCD to the external circuit. |
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| 4014. |
Principle of heat exchange: |
Answer» Solution :Suppose TWO objects A and B at different TEMPERATURE `T_(1)` and `T_(2)` respectively are enclosed in a box of heat resistant material as shown in figure.  Let `m_(1) `= MASS of A, `m_(2)` = mass of B,`c_(1) = ` specific heat capacity of A, `c_(2)=` specific heat capacity of B and T = common temperatureattained by A and B after the heat exchange between A and B. Here,no heatleaves the box or enters the box from outside. Hence, if` T_(1) GT T_(2)`, heat energy lost by `A( Q_(1))` = heat energy gained by `B(Q_(2))`. `:. m_(1)c_(1)(T_(1)-T) = m_(2)c_(2)(T-T_(2))` |
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| 4015. |
A chemical compound X is used in the soap and glass industry. It is prepared from brine. Write the chemical name, common name and chemical formula of 'X'. |
| Answer» SOLUTION :SODIUM carbonate, washing soda, `Na_(2)CO_(3).10H_(2)O` | |
| 4016. |
The fusion process can be carried out only at a temperature of ......... |
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Answer» `1000^(@)C` |
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| 4017. |
What is meant by power of accomodation of the eye ? |
| Answer» Solution :The ABILITY of the eye lens to adjust its FOCAL length to view objecs at different distances clearly is KNOWN as the POWER of accomodation. | |
| 4018. |
Calculate the momentum of a toy car of mass 200g moving with a speed of 5 m/s. |
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Answer» SOLUTION :Mass of the TOY car (m)=200G =0.2 kg Speed (v)=5 m/s Momentum (p)=m x v =0.2 x 5 =1 kg m/s |
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| 4019. |
Positive magnification : Erect image : : Negative magnification : …………. . |
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Answer» |
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| 4020. |
The relation between u, v and f for a mirror given by: |
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Answer» `F=(UV)/(u-v)` |
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| 4021. |
Which part of sunlight used in making a solar cell? |
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Answer» INFRARED radiation |
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| 4022. |
Draw a circuit diagram for a circuit consisting of a battery of five cells of 2 volts each, a 5 Omegaresistor, a 10 Omega resistor and a 15 Omega resistor, an ammeter and a plug key, all connected in aeries. Also connect a voltmeter to record tht: potential difference across the 15 Omega resistor and calculate : (i) the electric current passing through the above circuit and (ii) potential difference across 5 Omega resistor when the key is closed. |
Answer» SOLUTION :(i)  10 V battery Rest COMPONENTS Equivalent resistance =`R_(1)+R_(2)+R_(3)` `=5+10+15` `=30 Omega` Current in the CIRCUIT `I= (V)/(R)` `I = (10V)/(30Omega) = (1)/(3) A ` or 0.33 A (ii) Potential difference across 5 `Omega` resistor V= IR `=(1)/(3)A xx5 Omega` 1.67 V |
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| 4023. |
A and B are arguing about uniform accerelation. A states that accelarton means "the linger you gop." B states that accerelaton means " the further you go." Who is right? |
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Answer» A |
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| 4024. |
MnO_(2) + 4 HCI rarr MnCI_(2) + 2H_(2)O + CI_(2). Identify the substance oxidized in the above equation. |
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Answer» `MnCI_(2)` |
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| 4025. |
Why closed path is required for the flow of current? |
| Answer» Solution :CLOSED path is required for the flow of CURRENT because if the path is not closed, the circuit will break which will MEAN that between the two ends air is present. Since we know that air is an INSULATOR, it will not allow the flow of charges through it and the current will not flow. | |
| 4026. |
In upper atmosphere the kinetic temperature of air is of the order of 1000 K even then one feels severe cold in these places. Why? |
| Answer» Solution :As we GO at higher altitude the density of air decreases. So distances between molecules increases DUE to less number of collisions between them. Due to above reason speed of air molecules kinetic TEMPERATURE are of order 1000 K but due to higher altitude the temperature decreases as the RADIATION from earth takes LONGER distance. | |
| 4028. |
Name any one material used to make a solar cell and also mention the range of voltage produced by a typical cell. |
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Answer» Solution :SILICON, Germanium. Each solar CELL PRODUCES a voltage of 0.5 VOLT. |
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| 4029. |
In normal human eye, the image is formed |
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Answer» BEHIND RETINA |
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| 4030. |
The observations made by Swarali while doing the experiment are given below. Based on these write answers to the questions: Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium. Draw the diagrams of.three observations made by Swarali. |
Answer» SOLUTION :
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| 4031. |
The observations made by Swarali while doing the experiment are given below. Based on these write answers to the questions: Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium. What is the process of reflection of incident ray into denser medium called? |
| Answer» Solution :The PROCESS of reflection of INCIDENT RAY into denser MEDIUM is called TOTAL internal reflection. | |
| 4032. |
The observations made by Swarali while doing the experiment are given below. Based on these write answers to the questions: Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium. What is the specific value of anglei called? |
| Answer» SOLUTION :The SPECIFIC VALUE of `anglei` is called critical ANGLE. | |
| 4033. |
Nostoc, Anabaena : Biofertilizers : : Alfalfa : ….. |
| Answer» SOLUTION :PHYTOREMEDIATION | |
| 4034. |
We have a concave mirror of 10 cm focal length. Minimum distance between a real object and its real image formed by the mirror will be- |
| Answer» Solution :0. When object is placed at CENTRE of CURVATURE of concave mirror, its image is FORMED at the same position. | |
| 4035. |
The scientist who first demonstrated that sunlight is composed of seven colours is |
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Answer» Maxwell |
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| 4036. |
Differentiate ore and mineral |
Answer» SOLUTION :
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| 4037. |
The image of the object placed at focous is found at ………… by a convex lens. |
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Answer» |
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| 4038. |
Which principle is used to measure the specific heat capacity of a substance? |
| Answer» SOLUTION :The PRINCIPLE of heat exchange is USED to measure the SPECIFIC heat CAPACITY of a substance. | |
| 4039. |
Explain the role of fuse in series with any electrical appliance in an electric circuit. Why should a fuse with definite rating for an electric circuit not be replaced by one with a larger rating ? |
| Answer» SOLUTION :Fuse is a safety device connected in series with LIVE wire or with any electrical appliance in an electric circuit. It stops the flow of unduly high electric current in the circuit by GETTING melted due to rise in temperature as per Joule.s law of heating. High rating fuse wire has the larger CAPACITY. So it will not stop the flow of any relatively high current. Therefore, electrical devices cannot be protected from the POSSIBLE damage. | |
| 4040. |
What is an electromagnet ? Draw a circuitdiagram to show how a soft-iron piece can be transformed into an electromagnet . |
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Answer» Solution :An electromagnet is a magnet in which a magnetic field is produced by an electric current. Itgenerally consists of a core made of magnetic material surrounded by a coil through which an electriccurrent is PASSED to magnetise the core. A soft-iron piece can be transformed intoan electromagnet by winding insulated COPPER WIRE AROUND it [to form a solenoid] and connecting the two ends of the wire to a battery as shown in the figure. The soft-iron piece behaves as a powerful magnetwhen a current is passed through the solenoid. When the current is switched off, the iron core loses its magnetism and ceases to be an electromagnet . Thus, electromagnets are temporarymagnets. 
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| 4041. |
What type orf changes occurs in a home having chronically ill old person? How will you help to maintain good atmosphere ? |
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Answer» Solution :1. A chronic disease is a long-term condition that generally does not get better on its own and is generally not completely. 2. Having a chronically oil old person in a home would have common IMPACTS on the lives of other family members. 3. The common areas might be similarly affected which includes emotional impact, fincncial aspects, social life, time commitment, personal relationship and family ctivaties such as vaccation etc. So, in order to maintain good ATMOSPHERE, following things should be taken in account. 1. Make them comfortable and happy with compassionate behaviour. 2. Dont't stay away from them, instead listen to them. Provide REAL support, discuss family matters and communicate with them lovingly. 3. Family members should UNDERSTEND the moral values and responsiblilities towards their ill or AGED parents or other membgers. Evaryone should remember the proverb. "As you show so shall you reap". |
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| 4042. |
A converging and a diverging of equal focal length are placed co-axially in contact. Find the focal length and power of the combination. |
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Answer» Solution :Let f and -f are be the focal length of the CONVERGING and DIVERGING lens respectively then focal length of the combination 1/F = 1/f- 1/f = 0 power of the combination p=1/F=0 |
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| 4043. |
One of the following is not a required in the formation of biogas in a biogas plant. This is : |
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Answer» cow-dung |
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| 4044. |
Complete thefission reaction: ""_92U^(235)+""0n^(1) to ""_38Sr^(90)+Xe + 3""_0n^(1) |
| Answer» SOLUTION :`""_(92)U^(235)+""_0n^(1)to ""_(38)Sr^(90) +""_(54)Xe^(143)+""_(0)n^(1)` | |
| 4045. |
State Joule law of heating |
| Answer» SOLUTION :As pe Joule.s law the HEAT produced in a resistor is given as `H=I^2 RT` | |
| 4046. |
Which of the following animals can regenerate it's broken body part ? |
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Answer» Cockroach Cockroach , sparrow and frog cannot PERFORM regenration . Only echinoderms SHOW power of regeneration . So only starfish can regenerate its broken part. |
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| 4047. |
Watch the video clip of fire fighting mock drill on Yout tube and send to your friends and relative. |
| Answer» SOLUTION :STUDENTS are EXPECTED to PERFORM this ACTIVITY on their own. | |
| 4048. |
What does the divergence of magnetic field lines near the end of a current-carrying straightsolenoid indicate ? |
| Answer» Solution :The DIVERGENCE of MAGNETIC field LINES INDICATES the DECREASE instrengthof the magnetic field near the ends of the solenoid . | |
| 4049. |
The human eye can focus object at different distances by adjusting the focal length of eye lens. This is due to |
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Answer» presbyopia |
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| 4050. |
What are the steps taken by government for stopping cyber crime ? |
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Answer» Solution :1. 'Cyber crime unit' has been newly launched N police department. 2. Cyber crime experts collects details, investigate the cybercrime and thereby FIND the criminal with the help of internet. 3. IT Act-2000 act has been enacted since `17^(th)` October 2000 and been amended in 2008. 4. Person COMMITTING cybercrime has to face punishment like imprisonment for 3 years of fine upto 5 lakhs. 5. Maharashtra is at forefront in controlling cybercrimes and it has been proved to be the first state to start a separate cybercrime unit. |
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