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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.
| 3151. |
A student carries out the experiment of tracing the path of a ray of light through a rectangular glass slab, for two different values of angle if incidence /_i=30^(@) and /_i=45^(@). Find the set of values of the angle of refraction (/_r) and the angle of emergence (/_e)she is likely to observe in the two cases. |
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Answer» SOLUTION :The angle of refraction must be less the angle of INCIDENCE. ALSO angle of emergence is equal to angle of incidence. (i) `{:("When",/_i=30^(@),,/_r=20^(@),"and ",/_e=30^(@)):} (II) `{:("When",/_i=45^(@),,/_r=5^(@),"and ",/_e=45^(@)):} |
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| 3152. |
Name two natural resources which are like supporting systems. |
| Answer» SOLUTION :SOIL and WATER. | |
| 3153. |
(a) Draw a sectional view of human female reproductive system and label the part where (i) eggs develop (ii) fertilsation take place. (iii) fertilised egg gets implanted. (b) Describe, in brief, the changesthe uterus undergoes (i) to receive the zygote. (ii) if zygoteis not formed. |
Answer» Solution :(a) Sectional VIEW of human female reproductive system `:`  Parts where `:` (i) eggs develop -Ovary (ii) fertilisation take place -Fallopian tubes (iii) FERTILISED egg gets implanted -Uterus (b) (i) The innerof the uterus BECOMES thick and soft with lots of blood capillaries before release of a fertilised egg (zygote). The uterus has to keep this zygote for further development and supply it with food, OXYGEN, etc. (ii)If no fertilization occus then the thick uterus lining breaks down along with its bloods vessels in the form of vaginal bleeding called MENSTRUAL flow. |
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| 3154. |
You measure two quantities as A=1.0m+-0.2 m, B=2.0m+-0.2m. We should report correct value for sqrt(AB)as |
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Answer» `1.4m+-0.4m` |
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| 3155. |
Define the unit of resistance ? (or) Define one ohm. |
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Answer» Solution :Resistance of a CONDUCTOR is said one ohm if a CURRENT of one ampere FLOWS throug it when a potential difference of one VOLT is maintained across its ends. Ohm `=("1 volt")/("1 ampere")` |
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| 3156. |
A convex lens forms a real and inverted image of a pencialat a distance of 60 cm from the lens.The image formed is of the same size as the object. Find the focal length and power of the lens. At what distance is the pencil placed from the lens. ? |
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Answer» <P> Solution :Data : Convex lens,v = 40 cmM = -1,f = ?`h_(1)= ? , u = ? `` M = -1 = v/u` v = -v =-40 cm The pencil is placed at 60 cm from the convex lens. ` 1/f = 1/u = ( 60 cm) =1/( - 60 cm) = 2/( 60 cm)` ` f = (40 cm)/2 = 30 cm ` The FOCAL length of the lens = 30 cm ` P = 1/f= 1/(30 cm) = 1/(0.3 m) = 3.3D` The power of the lens = 3.3 D |
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| 3157. |
Do all liquids expand on heating? give an example. |
| Answer» SOLUTION :All liquids do not expand on HEATING. If water is HEATED from `0^(@)C` to `4^(@)C` it contracts | |
| 3158. |
Due tot which similar characteristics honey bee and cockroach are included in the same phylum ? |
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Answer» WINGS |
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| 3159. |
Name a mirror that can give an erect and enlarged image of an object. |
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Answer» PLANE mirror |
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| 3160. |
State the properties of ethanoic acid. |
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Answer» Solution :(1) Ethanoic acid is a colourless liquid with boiling point `118^(@)C` and MELTING point `17^(@)C.` It has a punget odour. (2) Its aqueous solution is acidic and turns blue litmus RED. (3) `A5%-8%` aqueous solution of acetic acid is USED as vinegar. (4) It is a weak acid. |
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| 3161. |
To construct a ray diagram we use two rays of light which are so chosen that it is easy to determine their directions after reflection from the mirror. Choose these two ras and state the path of these raysafter reflection from a concave mirror . Use these two rays to find the nature and position of the image of an objectplced at a distance of 15 cm from a concave mirror of focal length 10 cm. |
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Answer» Solution :Ray 1 . When and incident ray of LIGHT is parallel to the principal axis of a concave mirror, its reflected rays must pas through the principial focus of the concave mirror. Ray 2 . A ray PASSING through the principal focus of a concave miror after REFLECTION will emerge parallel to the principal axis. Focal length `=` 10 cm. Then centre of curvature , `C= 20 cm` Object isplaced at 15 cm, i.e., between F & C When the object formed is real, INVERTED and magnified . It is formed beyond C 
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| 3162. |
__________ is used to provide protection to the electrical components. |
| Answer» SOLUTION :GROUND CONNECTION | |
| 3163. |
Electrical energy generation and Enivronment. |
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Answer» Solution :The energy obtained through the fossil fuels as well as nuclear energy can cause degradation of the environment. If such energy sources are used, they can cause harm to the environment. (1) The burning of fossil fuels cause air pollution. The incomplete combustion of fossil fuels cause release of carbon monoxide. Some more TOXIC gases and soot particles cause various respiratory diseases. The carbon dioxide produced through all the combustion is creating global warming which is resulting into climate CHANGE. The nitrogen dioxide released through burning is responsible for acid RAINS. (2) Fossil fuels are limited due to their reserves are getting fast depleted. It has taken millions of years for the fossil fuels to form. The exploration of such fuels also cause enviromental degradation. The excavation can bring about marine pollution too. (3) In production of nuclear energy, there is a great risk of accidents. The safe disposal of nuclear waste is also a problem. (4) In ORDER to satisfy the ever-increasing demand for the energy, researchers are working hard on clean energy alternatives. Hydroelectric power from water reservoirs, wind power from wind, SOLAR energy from sun and electricity from biofuels are eco-friendly alternatives which may not harm the environment. |
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| 3164. |
For the circuit shown in the following figure,determine the eqUivalent resistance between points A and B. Also find the current I flowing through the circuit. |
| Answer» SOLUTION :`10Omega,1A` | |
| 3165. |
At what height from the center of the Earth the acceleration due to gravity will be 1/4th of its value as at the earth. |
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Answer» Solution :Given: Height from the CENTRE of the Earth, R. =R+h The acceleration DUE to gravity at that height, g. = `g//4` Formula: g=`(GM)/(R^(2))` `(g)/(g)=((R)/(R))^(2)` =`((R+h)/(R))^(2)=[(R)/(R)+(h)/(R)]^(2)` =`[1+(h)/(R)]^(2)` 4=`[1+(h)/(R)]^(2)` Apply root on both sides `2=[1+(h)/(R)]` orh=R R’=2R From the centre of the Earth, the object is placed at twice the radius of the earth (ii)" How many electrons are passing PER second in a circuit in which there is a current of 5A." "Current I = 5A Timet - 1 second" "Charge of electron (e) = `1.6xx10^(-19)C` I=`(q)/(t)=(ne)/(t)`" "Number of electron", n =`(It)/(e)` =`(5xx1)/(1.6xx10^(-19))` n=`3.125xx10^(19)` |
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| 3166. |
What are the differences between simple microscope and compound microscope. |
Answer» SOLUTION :
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| 3167. |
………..is a metal which is in liquid form at ordinary temperature and pressure. |
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Answer» MAGNESIUM |
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| 3168. |
How does the refractive index of a medium depend on its temperature ? |
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Answer» |
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| 3169. |
If U-235 is bombarded with a neutron, it gets converted into U-237. |
| Answer» SOLUTION :FALSE. It GETS CONVERTED into U-236. | |
| 3170. |
An object is kept at 20 cm in front of a convex lens and its real image is formed at 60 cm from the lens . Find the height of the image if the height of the object is 6 cm. |
| Answer» SOLUTION :`h_(2)=-18 CM` | |
| 3172. |
Persons spending lot of time with cell phones for several hours are extemely aware of the surroundings. |
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Answer» Solution :False. Personns SPEEDING lot of time with cell PHONES for secveral hours are USUALLY UNAWARE of the surroundings. |
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| 3173. |
The red colour of the sun at the time of sunrise and sunset is because : |
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Answer» Scattering |
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| 3174. |
If the body in Ex. (28) is moving at 100 m/s on the earth's surfarce, what will be its (i) kinetic energy (ii) total energy ? |
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Answer» Solution :Data : `m=20kg, v=100m//s` (i) The KINETIC energy of the body `=(1)/(2)mv^(2)=(1)/(2)xx20kgxx(100m//s)^(2)=10^(6)J.` (II) The total energy of the body = kinetic energy + potential energy `=10^(5)J+(-1.2555xx10^(9)J)` `=(1-12544)xx10^(5)J=-12543xx10^(5)J` ltbr `=-1.2543xx10^(9)J.` |
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| 3175. |
When two bodies stick together after collision, the collision is said to be |
| Answer» SOLUTION :INELASTIC COLLISION. | |
| 3176. |
Photolysis is a decomposition reaction caused by____ |
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Answer» heat |
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| 3177. |
Figure below shoes the use of a lever. (a) State the principle of moments as applied to the above lever. (b) To which class of lever does it belong ? Give an example of this class of lever. (c) If FA=10 cm, AB=490 cm, calculate: (i) the mechanical advantage, and (ii) the minimum effort required to lift and load (=50N). |
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Answer» (b) CLASS III, sugar TONGS (C) (i) M.A.`=(1)/(50),` (II) Effort=2500 N. |
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| 3178. |
What is optical density? |
| Answer» Solution :Optical density is the measure of absorption per unit distance of incident LIGHT by a material. When a beam of light enters into any material, some of it is absorbed by the material. This absorption RATE varies from tnaterial to material and is ALSO different for radiation of various wavelengths for a PARTICULAR material. | |
| 3179. |
The laws of reflection hold true for : |
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Answer» PLANE MIRRORS only. |
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| 3180. |
Magnification of mirror is +2/3, the type of mirror is : |
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Answer» Concave |
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| 3181. |
An electric iron is connected to the mains power supply of 220V. When the electric iron is adjusted at 'minimum heating' it consumes a power of 360W but at 'maximum heating' it takes a power of 840W. Calculate the current and resistance in each case. |
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| 3182. |
Give the signincance of the following in a domestic circuit : (i) electric meter (ii) earthing (b) List two precautions that should be taken to avoidoverloading. |
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Answer» Solution :(a) (i) Electric meter : It is used to RECORD the consumption of ELECTRICAL energy in kWh in the circuit. (ii) Earthing : It prevents electric shock. The earth wire is joined to the METAL case of the appliance and . provides a LOW resistance conducting path for the current. (b) (i) Too many appliances should not be connected to a single SOCKET. (ii) Fuse of current rating 5A and 15A should be separately used in the domestic circuit. |
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| 3183. |
Mention any two advantages and two disadvantages of producing hydroelectricity by building dams on rivers. |
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Answer» Solution :Advantages: (i) The generation of ELECTRICITY from water does not produce any environmental pollution. (ii) Water energy is a renewable sources of electric energy which will never get exhausted. Disadvantages: Disadvantages: (i) A vast VARIETY of FLORA and FAUNA ( plants and animals ) get affected . (ii) Dams can be CONSTRUED only at a limited number of places. |
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| 3184. |
Mr. Vinay's 65 years old mother is complaining about blurred vision in both the eyes due to which the cannot see things clearly. Mr. Vinay took his mother to an eye hospital. The doctor examined the eyes of his mother carefully and concluded that she has a medical condition which could not be corrected by using any type of spectacle lenses and it required surgery. The mother's eyes were operated upon and she could see properly once again. (a)What could be the defect in the eyes of Mr. Vinay's mother ? (b) What has happened to the eye lens during this defect ? (c) What is done during surgical operation of eyes to restore the correct vision ? (d) What would happen if eye surgery of a pereson having this defect in not done ? (e) What values are shown by Mr. Vinay in this episode ? |
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Answer» Solution :(a) The defect in the eyes of Mr. Vinay mother is known as cataract. (b) During the development of cataract, a membrane is GRADUALLY formed over both the eye-lenses making the eye-lenses cloudly. This make the vision blurred. (c) During SURGICAL operation, the cloudy eye-lenses are removed from the eyes and suitable artificial lenses are inserted in their place. (d) If the eye surgery of a person having cataract is not done then the vision of this person will go on BECOMING more and more blurred, and ultimately the person would not be able to see anything at all. (e) Mr. Vinay shows the values of (i) Awareness or knowledge (that eye-defects can be cured by eye-specialist doctors) (ii) Desire to mitigate the sufferings of OTHERS (here mother), and (iii) SENSE of responsibility (towards old mother). |
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| 3185. |
Larvae of ……………. ,metamorphose into adults after settling down at bottom of the sea. |
| Answer» Solution :LARVAE of Urochordata metamorphose into ADULTS after settling down at BOTTOM of the sea. | |
| 3186. |
The speed of light in air is 3xx10^(8)ms^(-1). Calculate the speed of light in glass. The refractive index of glass is 1*5. |
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| 3187. |
Which has low penetrating power? |
| Answer» Solution :`alpha` rays | |
| 3188. |
What is this law knowas ? |
| Answer» Solution :Refractive INDEX of the second medium with respect to the first medium (N) = `(SIN i)/(sin r)` Here, I is the angle of INCIDENCE and r is the angle of refraction . | |
| 3189. |
How does nuclear fission take place? |
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Answer» Solution :(i)When a slow moving neutron is bombarded onUranium - 235 nucleus, it ABSORBS the neutron and gets converted into its isotope Uranium - 236. (ii)Uranium - 236 being extremely unstable, converts into atoms of Barium and KRYPTON through a process of fission releasing three neutrons and 200 Me V ENERGY. 
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| 3190. |
It is very difficult to see through fog because |
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Answer» of scattering of LIGHT |
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| 3191. |
Toxic gas leakage : Accidentaldisaster : : War : …………….. |
| Answer» SOLUTION :INTERNATIONAL | |
| 3192. |
Rays from sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of the image is exactly equal to the size of the object ? |
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Answer» 30 cm in front of mirror To FORM an IMAGE of exactly same size as that of an object, the object should be placed at the CENTRE of curvature (u = R = 2f) of mirror. Hence, the object should be placed at 30 cm in front of mirror. |
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| 3193. |
A person who met with an accident lost control of body temprature ,water balance and hunger.Which of the following part of brain is supposed to be damaged? |
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Answer» HYPOTHALAMUS |
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| 3194. |
CALYX |
| Answer» SOLUTION :PROTECTION of INNER WHORLS of the FLOWER. | |
| 3195. |
How does the sky appear from the surface of the moon ? |
| Answer» Solution :The sky appears dark from the SURFACE of the moon because moon has no ATMOSPHERE to scatter SUNLIGHT. | |
| 3196. |
State -the law of volume. |
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Answer» SOLUTION :(i) When the pressure of gas is kept constant, the VOLUME of a gas is directly proportional to the TEMPERATURE of the gas. (II) `V prop T` or `(V)/(T)` = constant |
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| 3197. |
Commercial electric motors donot use |
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Answer» An ELECTROMAGNET to rotate the armature |
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| 3198. |
Ravi kept a book at a distance of 10 cm from the eyes of his friend Hari. Hari is not able to read anything written on the book. Why ? |
| Answer» Solution :It happens because the least distance of distinct VISION for normal HUMAN eye is 25 cm. This MEANS that an object has to be at least 25 cm away from the eye to be SEEN CLEARLY. | |
| 3199. |
The harnessing of which of the following leads to the destruction of large eco-systems ? |
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Answer» THERMAL POWER |
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| 3200. |
(a)Define critical velocity. (2)Derive the formula of critical velocity |
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Answer» Solution :(a)The satellite is given a specific velocity known as the critical velocity `(V_c)` in a tangential DIRECTION to the orbit. The satellite then starts revolving around the earth. (b) The formula for the velocity `v_c` can be DERIVED as below. If a satellite of mass 'm' is revolving around the earth in an orbit of height 'h' with speed `v_c` then as seen in the chapter on 'Gravitation' , a centripetal force `(mv_c^2)/r` will act on it. Here 'r' is theorbital RADIUS of the satellite from THECENTRE of the earth. This centripetal force is provided by the gravity of the earth. (c ) Therefore , centripetal force = gravitational force between the Earth and satellite. `(mv_c^2)/(R+h)=(GMm)/((R+h)^2)` `V_c^2=(GM)/(R+h)` `v_c=sqrt((GM)/(R+h))` |
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