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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.
| 5101. |
The image of an object formed by a mirror is real, inverted and is of magnification -1. If the image is at a distance of 40 cm from the mirror, where is the object placed? Where would the image be if the object is moved 20 cm towards the mirror? State reason and also draw ray diagram for the new position of the object to justify your answer. |
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Answer» SOLUTION :Object position: At C (Centre of curvature) Object distance =40 cm Position of the image - at infinity Reason: Focal length of the mirror = 20 cm If the object is moved 20 cm towards the mirror then it new position WOULD be at the FOCUS of the mirror.  (deduct 1/2 MARK if arrows are missing /not marked) |
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| 5102. |
IT Acts 2000 is to cantrol the _______________ |
| Answer» SOLUTION :IT Acts 2000 is to control the ` UL ( cyber CRIMES) ` | |
| 5103. |
Which cycles are operated in environment ?What is their importance ? |
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Answer» SOLUTION :i. The DIFFERENT cycles that operates in environment are water cycle, carbon cycle ,gaseous cycles such as nitrogen cycle, OXYGEN cycle, sedimentary cycles such as phosphorus cycle, calcium cycle, iron cycle , etc. ii. These cycles are important to maintainthe cyclic flow of nutrients within an ecosystem. Proper flow of nutrients through the biogeochemical cycles ENSURES ECOLOGICAL balance. |
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| 5104. |
A large force acting for a very short interval of time is called as ………………………….. |
| Answer» SOLUTION :IMPULSE FORCE | |
| 5105. |
Twinkling of stars is due to atmospheric |
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Answer» dispersion of LIGHT by WATER droplets. |
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| 5106. |
Find the power of a convex lens which forms a real, and inverted image of magnification -1 of an object placed at a distance of 20 cm from its optical centre. |
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Answer» Solution :Here u = - 20 CM and MAGNIFICATION m = -1 for real and inverted image `because""m = (v)/(u)`, hence `v = "MU" = (-1) xx (-20) = + 20` cm `THEREFORE""(1)/(f) = (1)/(v) - (1)/(u) = (1)/((+20)) - (1)/((-20)) = (1)/(20) + (1)/(20) = (1)/(10)` `rArr` f = 10 cm = 0.1 m `therefore` Power of convex lens `P = (1)/(f("in m")) = (1)/(0.1 m) = + 10 D` |
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| 5107. |
From the above table, Which substance can use to make insulators ? |
| Answer» SOLUTION :GLASS can USE to MAKE the INSULATORS. | |
| 5108. |
Electromagnetic induction occurs when |
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Answer» there is a RELATIVE MOTION between the COIL of a WIRE and a GALVANOMETER |
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| 5109. |
(a) What is long-sightedness ? State the two causes of long-sightedness (or hypermetropia). With the help of ray diagrams, show : (i) the ray-defect long-sightedness. (ii) correction of long-sightedness by using a lens. (b) What eye has a near point distance of 0.75 m. What sort of lens in spectacles would be needed to reduce the near point distance to 0.25 m ? Also calculate the power of lens required. Is this eye long-sighted or short-sighted ? An eye has a far point of 2 m. What type of lens in spectacles would be needed to increase the far point to infinity ? Also calculate the power of lens required. Is this eye long-sighted or short-sighted ? |
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| 5110. |
(i) Define power of a lens. Write its SI unit. (ii) You are provided with two convex lenses of focal length 15 cm and 25 cm, respectively. Which of the two is of larger power? Give reason for you answer. (iii) A 20 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 10cm. The distance of the object the lens is 15 cm. Find the nature, position and size of the image. Alsofind its magnification. |
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Answer» Solution :(i) Ability of a lens to converge or diverge light rays is TERMED as power of a lens. Power `=1/("Focal length")` SI UNIT of power is Diptre. (ii) Lens of focal length 15 cm is of larger power because power is inversely proportional to the focal length. (iii) `1/v-1/u=1/f` `1/v=1/(-15)+1/10` `=1/30:.v=30` cm IMAGE is real and inverted Magnification `=(h.)/h=v/u,m=-2` |
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| 5111. |
A bulb is rated 5V, 500 mA. Calculate the rated power and resistance of the bulb when it glows. |
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Answer» Solution :POTENTIAL DIFFERENCE : 5V CURRENT : 500 mA = 500 `xx10^(-3)` A P =VI `= 5Vxx500 xx10^(-3) A = 2.5 W ` `R = (V)/(I) = (5V)/(500xx10^(-3)A)xx10 Omega` `R = 100 Omega` |
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| 5112. |
The potential difference between two conductors is 110 V. How much work is moving 10C charge from one conductor to the other? |
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Answer» Solution :Potential DIFFERENCE, V = 110 V Charge, Q = 10C WORK done, W-? `V=(W)/(q)` =`qxxV` =`10xx110=1100J` |
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| 5113. |
What do you say about sound waves in air by the above activity? |
| Answer» Solution :From the above activity, we can SAY that there INVOLVES change in the density of medium while sound WAVES are travelling in air. | |
| 5114. |
A solar cooker may not cook food if : |
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Answer» the SOLAR cooker is not placed in the shade |
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| 5115. |
Draw a labelled diagram to show (i) reddish appearance of the sun at the sunrise or the sunset and (ii) white appearance of the sun at noon when it is overhead. |
Answer» SOLUTION :LABELLED DIAGRAM has been DRAWN here.
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| 5116. |
A boy recalls the relation for relativistic mass (m) in terms of rest mass (m_(0)) velocity of particle V, but forgets to put the constant c (velocity of light). He writes m=(m_(0))/((1-v^(2))^(1//2)) correct the equation by putting themissing ‘c’. |
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Answer» Solution :SINCE quantities of similar nature can only be ADDED or subtracted, `v^(2)` cannot be subtracted from 1 but `v^(2)//C^(2)` can be subtracted from 1. `therefore m=(m_(@))/(SQRT(1-v^(2)//c^(2)))` |
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| 5117. |
State any three reasons to justify that LPG is considerd E as an ideal fuel |
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Answer» Solution :LPG is considered as an ideal FUEL because • It is easy to STORE, handle and transport. • It produce large AMOUNT OFHEAT on BURING • It does not leave any residue on burning |
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| 5118. |
Ethanol is used on a large scale at commercial level. This is very useful chemical. It is commonly called alcohol and is the active ingredient of alcoholic drinks. But consumption of alcohol also causes drunkennes and this practice is socially condemned. Read the text given and answer the following questions (a) Give two chemical properties of ethanol (b) As a responsible student of the class, what steps would you take to discourage the use of alcohol ? |
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Answer» Solution :(a) (i) It is a colourless liquid at room temperature (ii) It has very low melting point (156 K) and low boiling point (351 K or `78^(@)C`). (b) By sensitizing people about harmful effects of LIQUOR CONSUMPTION, by making posters, banners and WRITING articles on this issue. |
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| 5119. |
Statement 1: Electric current (flow of electrons) creates heat in a resistor. Statement 2 : Heat in the resistor is created according to the law of energy conservation. Explain Statement 1 with the help of Statement 2. |
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Answer» Solution :i. When CURRENT flows through a resistor connected to a cell, ENERGY provided by the cell is RECEIVED by the resitor. ii. According to law of conservation of energy, this energy is USED to perform work on the resistor and is CONVERTED into heat energy. |
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| 5120. |
Plateletsplayan importantroleinclottingof blood . |
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Answer» LEUCOCYTES |
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| 5121. |
The forcewhich is equal to resultant but oppositein direction is called as __________. |
| Answer» SOLUTION :equillibrant | |
| 5123. |
When water of mass70g and temperature 50^(@)Cis added to water of mass 30g, the maximum temperature of the mixutre is found to be 41^(@)C. Find the temperature of water of mass 30g before hot water was added to it. |
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Answer» Solution :Data : `m_(1) = 70` g , `T_(1) = 50^(@)C , m_(2)= 30 g , T = 41^(@)C , T_(2)` = ? According to the principle of heat EXCHANGE ,heat LOST by hot water = heat gained by COLD water ` therefore m_(1)c (T_(1) - T) = m_(2) c (T - T_(2))` `therefore m_1T_(1) - m_1 T = m_(2) T - m_(2) T_(2)` `therefore m_(2) T_(2) = (m_(1) + m_(2)) T - m_(1) T_(1)` `therefore T_(2)= ((m_(1) + m_2) T - m_(1) T_1)/(m_(2))` `= ((70 g + 30 g ) 41^(@) C - 70 g xx 50^(@)C)/(30 g )` = `((100 xx 41 - 70 xx 50)/(30)) ""^(@)C` `= ((410 - 350)/(3)) ""^(@) C = (60)/(3) ""^(@)C = 20 ""^(@)C` This is the REQUIRED temperature . |
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| 5124. |
The minimum distance between an object and its real image formed by a convex lens (of focal length f) is |
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Answer» `f/2` |
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| 5125. |
Define orbital velocity of a nearest satellite revolving around the earth and obtain its expression. |
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| 5126. |
Derive expression for equivalent resistance of a parallel combination of resistances. (b) Calculate the ratio of equivalent resistance for a series combination of n number of identical resistors to the parallel combination of the same type of n number of resistors. |
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Answer» Solution :(b) Let value of each resistor be `R Omega` Then for series COMBINATION of N such RESISTORS, the EQUIVALENT resistance `R_s` is `R_s=R+R+…n time s= nR` If equivalent resistance for PARALLEL combination of these resistors be `R_p` then `1/R_p=1/R+1/R+......n time s=n/R` `implies R_p=R/n` `therefore R_s/R_p=(nR)/(R//n)=n^2` |
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| 5127. |
You have to use free space around your home for good purpose. |
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Answer» SOLUTION :(i) I will plant threes, FLOWERING plants and make a beautiful garden. I WILLL also arrange for space for outdoor games. (ii) I will see to it that it is nt LITTERED. (iii) It will be a place where I can invite my friends and play games. |
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| 5128. |
A person lives near a forest . Make a list of four items which he can get from the forest to meet his daily needs. |
| Answer» Solution :Firewood , small TIMBER , THATCH bamboo , fruits , NUTS and MEDICINES (Any TWO) | |
| 5129. |
Biogas is considered to be a boon to the farmers . Give reasons. |
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Answer» Solution :Biogas is considered to be a boon to the farmers because. (i) Farmers can produce clean domestic fuel from the wastes LIKE animals dung. dry LEAVES , dry plants , etc. (ii) Spent slurry can be used in the fields as manure to increase the fertility of the soil. (iii) Biogas can be used to generate electricity which can be utilised in run modern machines used in the FIELD to save TIME and energy. |
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| 5130. |
Whichof the followingstatements is false ? |
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Answer» The direction of the magneticline in a region OUTSIDE a bar magnet is from N to S . |
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| 5131. |
Show that a.(bxxc) is equal in magnitude to the volume of the parallelopiped formed on the three vectors a, b and c. |
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Answer» Solution :Let a parallelopiped be formed on threevectors ` vec(OA) = vec a, vec(OB) = vecb, vec(OC) = vecc` Now, `vecbxxvecc = bc sin 90^@ hatn = bc hatn`  where `hatn`is the UNIT vector along `BAR(OA)`perpendicular to the plane containing ` vecb " and " vecc` Nom, ` veca.(vecbxx vecc) a veca. bc hatn = (a)(bc)cos 0^@ = abc` Which is EQUAL is magnitude to the VOLUME of parallelopiped . |
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| 5132. |
The ionizing power of alpha rays is 10,000 times greater than ___________. |
| Answer» SOLUTION :`GAMMA`-RAYS | |
| 5133. |
Give the meaning of the term VIBGYOR. With which phenomenon is it connected ? |
| Answer» Solution :VIBGYOR represents the colour sequence in a visible specturm. `V` stands for VIOLET , I for indigo , B for blue , G for green , Y for yellow , O for orange and R for red. It is connected with the phenomenon of dispersion of white LIGHT. | |
| 5134. |
Define viscosity and write SI unit of coefficient of viscosity. |
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| 5135. |
Discuss the effects of these disasters on poublic life. |
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Answer» Solution :a. The COLLAPSING and submerging of the bridge caused due to flood not only leads to loss of life and property but ALSO disrupts the services. The interruption fo railway services due to water loging disrupts the overall life in suburban cities. The daily commuters as well as goods are not able to reach their destination in time. Also, in calamities like FLOODS, the flood water gets mixed with SEWAGE water, such contaminated water leads to spread of water borne diseases and other epidemics. c. The train derailment leads to huge loss of life as well as financial loss due to destriction of goods. d. Earthquakes can be extremely destructive dependin on its intensity. It leads to huge loss of life and property. Bringing normalcy to life in such conditions is very difficult and may TAKE a lot of time. |
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| 5136. |
True or False. The velocity of sound is independent of temperature . |
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| 5137. |
Increase in area per unit area at 0^(@)C per degree rise in temperature is ... |
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Answer» coefficient of LINEAR expansion |
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| 5138. |
The amount of vapour needed to ............ the air depends on the temperature of the air. |
| Answer» SOLUTION :SATURATE | |
| 5139. |
Imagine that you are sitting in a chamber with your back to one wall. An electronbeam, moving horizontally from the back wall towards the front wall, is deflectedby a strong magneticfield to your right side. What is the direction ofthe magneticfield. ? |
| Answer» SOLUTION :ACCORDING to Fleming.s left-hand RULE, the DIRECTION of magnetic FIELD is vertically downwards. | |
| 5140. |
How can we measure electric current ? |
| Answer» SOLUTION :An AMMETER is USED to ELECTRIC CURRENT. | |
| 5141. |
The frequency of sound is 10 Hz. How many times does it vibrate in one minute? |
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Answer» SOLUTION :Number of vibrations per second = 10 Number of vibrations in one MINUTE `= 10 xx 60 = 600` |
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| 5142. |
Explain whya horse cannot pull a cart and run in empty space |
| Answer» Solution :While TRYING to pull a cart , a horse pushes the ground backwards with a certain force at an ANGLE . The ground offeres an equal reaction in the opposite DIRECTION , on the horse . The FORWARD COMPONENT of this reacion is responsible for motion of the cart . In empty space , there is no reaction and hence , a horse cannot pull the cart and run . | |
| 5143. |
The force which produces centripetal acceleration is called _________. |
| Answer» SOLUTION :CENTRIPETAL FORCE | |
| 5144. |
No matter how far or close you stand from a mirror, your image is always virtual and erect. The mirror is |
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Answer» convex MIRROR |
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| 5145. |
When is air said tobe unsaturated with water vapour ? |
| Answer» Solution :When AIR contains WATER vapour less than its capacity to HOLD water vapour at that temperature, it is said to be UNSATURATED with water vapour. | |
| 5146. |
The resistance of a conducting wire is 10 Omega. If a battery of 1.5 V is connected to it, the electric current flowing through it will be ………………….. . |
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Answer» 0.15 mA `:. I = V/R = 1.5/10 =0.15` `=150 XX 10^(-3)` `=150 mA` |
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| 5147. |
Principle invented by Michael Faraday on which an electric generator works |
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Answer» |
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| 5148. |
How can change of size of eyeball be one of the reason for (i) myopia and (ii) herpmetropia eye ? Compare the size eyeball with that of a normal eye in each case. How does this change of size affect the position of image in each case ? |
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Answer» SOLUTION :(i) In an eye suffering from myopia, the EYEBALL is elongated compared to that of a NORMAL eye. Due to this, the image is formed in front of the retina instead of on the retina. (ii) In an eye suffering from hypermetropia, the eyeball is too small in LENGTH compared to that of a normal eye. Due to this the image is formed behind the retina instead of on the retina. |
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| 5149. |
According to charles's laws , at constant presssure the temperature is inversely proportional to volume . |
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Answer» <P> `V prop T (or) T prop V` |
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| 5150. |
Define : Principal focus of a convex lens. |
| Answer» SOLUTION :PRINCIPAL focus is a point on the principal axis, at which a beam of parallel RAYS are covnerged after REFRACTION. | |