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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.
| 4501. |
Differentiate is real image from a virtual image giving two points of difference. |
Answer» SOLUTION :DIFFERENCE between REAL IMAGE and VIRTUAL image.
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| 4502. |
Tell me who am I ? What is my class/phylum ? I stay inside two shells. My body is divided into head , foot and visceral mass. |
| Answer» SOLUTION :BIVALVE or OYSTER , PHYLUM : MOLLUSCA. | |
| 4503. |
For performing an experiment, a student was asked to choose one concave mirror and one convex lens from a lot of mirrors and lenses of different kinds. The correct procedure adopted by her will be : |
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Answer» To choose a MIRROR and lens which can from an ENLARGED and erect IMAGE of an object. |
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| 4504. |
Assertion : Gamma rays, penetrates through materials most effectively. Reason : Gamma rays, which have the shortest wavelengths of all electromagnetic radiation. |
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Answer» If both the assertion and the reason are TRUE and the reason is the CORRECT explanation of the assertion. |
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| 4505. |
Which colour of white light suffers (i) least deviation and (ii) maximum deviation when a beam of white light passes through a glass prism? |
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Answer» SOLUTION :(i) Least DEVIATION : RED. (II) Maximum deviation : VIOLET. |
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| 4506. |
What is silviculture ? |
| Answer» Solution :It is a branch of FORESTRY which is concerned with ESTABLISHMENT of CARE and reproduction of MONOCULTURES of valuable TREES. | |
| 4507. |
Convex lenses are used in making microscope , telescope and slide projectors. |
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| 4508. |
Other than thermal power plant, which power plants use thermal energy for power generation ? In wahat different ways is the thermal energy obtained ? |
| Answer» Solution :Apart from thermal power plant, power PLANTS BASED on nucear ENERGY and SOLAR thermal power plants use thermal energy for power generation. | |
| 4509. |
Internet is my friend. Complete the table given on page 51 of your textbook for some important nuclear power plants in India. |
Answer» SOLUTION :
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| 4510. |
You accelerate your car forward. What is the direction of the frictional force on a package resting on the floor of the car ? |
| Answer» Solution :The package in the accelerated CAR (a non inertial frame) experiences a Pseudo force in a DIRECTION opposite to that of the motion of the car. The FRICTIONAL force on the package which ACTS opposite to this pseudo force is thus in the same direction (forward) as that of the car. | |
| 4511. |
A uniform metre rule rests horizontally on a knife edge at the 60cm mark when a mass of 10g is suspended from one end. Draw a diagram of the arrangement. (a) At which end must this mass be suspended (b) What is the mass of the rule? (c ) THe 10g mass is now shifted to the 90cm mark. In which direction must the knife edge be shifted to make the rule horizontal again? |
Answer» Solution :(a) Fig. 1.22 shows a UNIFORM metre rule ABwhich rests horizontally on the knife edge at O (60 cmmark). Let Mg be the mass of the rule . A uniform rule has same distribution of mass throughout its length, so its weight Mg will act at its middle point i.e., at the 50cm MARK.  The weight Mg of the rule PRODUCES an anti-clockwise moment about the knife edge O. In order to BALANCE it, 10g mass must be suspended at the end B (i.e., at the mark 100cm) to produce a clockwise moment about the knife edge O. (b) From the principle of moments Anticlockwise moment= Clockwise moment `Mg times (60 -50)=10g times (100-60)` or `Mg times 10=10 g times 40` `therefore` Mass of rule M=40g When the 10g mass is shifted to the 90cm mark, its distance from the knife edge reduces resulting in decrease of clockwise moment. SO the knife edge must be shifted away from the 10g mass to reduce the distance between the knife edge and mass M so as to make the anticlockwise moment byM equal to the reduced VALUE of clockwise moment. |
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| 4512. |
Assertion (A) : In the process of nuclear fission, the amount of nuclear energy generated by the fission of an atom of uranium is so tremendous that it produces 10 million times the energy produced by the combustion of an atom of carbon from coal.Reason (R) : The nucleus of a heavy atom such as uranium, when bombarded with low energy neutrons, splits apart into lighter nuclei. The mass difference between the original nucleus and the product nuclei gets converted to tremendous energy. |
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Answer» Both (A) and (R) are TRUE and (R) is CORRECT EXPLANATION of the assertion. |
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| 4513. |
How much energy is consumed by 2 kW AC when used for 2 hour? |
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Answer» <P> Solution : Electric ENERGY `E = P xx t``= 2 kW xx 2"HOUR"` `=4kWh` Where, 1KWH `= 3.6 xx 10^6 J` |
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| 4514. |
Moment of inertia of a body does not depend on |
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Answer» MASS of object |
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| 4515. |
Derive the formula of the heat energy produced in the conductor because of electric current flows in it for the relax time-interval .t.. Give its unit. |
Answer» Solution :A metallic conductor (or a resistance wire) offers resistance to the FLOW of current, so work must be done by the current-source for a continuous flow of electric current through a conductor.  Consider a current I flowing through a resistor (or conductor) of resistance R. Let V be the potential difference across the resistor (see figure). Let t be the time-interval during which a charge Q flows through the resistor (conductor). The work done by the current source in moving charge Q through a potential difference V is vg. THEREFORE, the current source must supply energy to the circuit equal to VQ in time t. Thus, energy spent by the source or thework done by the source, `W = VQ` `= V ("It") ( :. I = Q/t)` `=(IR) ("It")` (By the Ohm.s law V =IR) `:. W = I^2Rt... ....(12.15)` This electrical energy gets dissipated as heat in the resistor. Thus for a steady current I, the AMOUNT of heat H generated (produced) in time- interval t is `H = I^2 Rt`.......(12.16) This is known as the Joule.s law of heating. The SI unit of electrical energy and heat energy is the joule (J). Its other UNITS are watt-second (Ws) and kilowatt-hour (kWh) or unit (commercialunit for electrical energy). |
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| 4516. |
Define one kilocalorie ? |
| Answer» Solution :One KILOCALORIE is the AMOUNT of HEAT energy required to rise the TEMPERATURE of 1 kilogram of water through `1^(@)C`. | |
| 4517. |
Fig. 11.11 shows an experimental set up for observing a phenomenon of light in colloidal solutions. A student dissolves about 200 g of sodium thiosulphate (hypo) in about 2 L of clean water in the tank and adds about 1 to 2 mL of concentrated HSO4 to the water. What would he observe after the source of light S is switched on (i) from the three sides of the glass tank? (ii) from the fourth side of the glass tank facing the circular hole ? Give reason. |
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Answer» Solution :(i) From three sides of the glass tank blue LIGHT is obtained due to scattering of light of short wavelengths by MINUTE colloidal sulphur particles. (ii) From the fourth side of the glass tank facing the circular hole, first the orange-RED and then BRIGHT crimson red coloured light is observed. It is due to the FACT that red light of longer wavelength suffers very little scattering and travels straight through the tank. |
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| 4518. |
Give three examples of activaties under the jurisdication of cyber crime laws. |
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Answer» Solution :i. Hacking of information of government, instituties and companies through internet. ii. Teasing and financial exploitation of people through social medial. iii. Piracy of softwere, literature, photos, videos, music, etc. obtained from internet. iv. Bank transcations carried out using pIN without the knowledge of consumers. v. Selling of inferior quality itmes than those shown on shopping websites. vi. MISUSE of electronic media for sending derogatory massages, circulating vulgar pictures and inflammatory statements. VII. Spreading of unwanted messages or emails which can impair or LEAD to shutdown of MOBILES and computers. |
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| 4519. |
How do butterflies contribute to environment balance ? |
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Answer» Solution :i. Pollination is essential for plant reproduction and butterflies are effective POLLINATORS. ii. Butterflies also forma food SOURCE for predators like birds, reptiles, ETC. iii. These creatures are sensitive to changes in climate and pollution. IV. They are indicators of a healthy ENVIRONMENT and a healthy ecosystem. |
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| 4520. |
The force of rcpulsion between two parallel wires is f when each one of them carries a certain current I. If the current in each is doubled, the force between them would be |
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Answer» 4/f `THEREFORE F prop I_(1) I _(2)` Given` f peop I ^(2)` `f . (2I)^(2) prop 4I^(2)` `therefore f . =4f` |
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| 4521. |
Concave lens is used to correct hypermetropia. |
| Answer» SOLUTION :CORRECT statement- Concave lens is USED to correct myopia. | |
| 4522. |
Whichof the followingis atriatomicmolcule ? |
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Answer» GLUCOSE |
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| 4523. |
Assertion: LED bulbs are far better than incandescent bulbs. Reason: LED bulbs consume less power than indanescent bulbs. |
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Answer» If both the assertion and REASON are true and the reason is the correct EXPLANATION of the assertion. |
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| 4524. |
What is the commonly used name for the power plant located near Mumbai? |
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Answer» BARC |
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| 4525. |
A convex lens forms a real, diminished point sized image on focus. Then the position of the object is at |
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Answer» focus |
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| 4526. |
Draw the diagram of an elecbic motor and labe'l the following parts. (i) Split rings(b) Brushes Two ways to increase the strength of the field of a solenoid: |
Answer» SOLUTION :
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| 4527. |
Discuss the gamma decay process with example. |
| Answer» SOLUTION :In a `gamma` - decay, only the ENERGY level of the nucleus changes. The ATOMIC number and MASS number of the radioactive nucleus remain the same. | |
| 4528. |
Natural uraniumU-238 is the core fuel used in a nuclear reactor. : True or False |
| Answer» Solution :Correct Statement: U-238 is not a fissile material but are abundant in nature. But in REACTOR this can be converted into a fissile material `PU^(239)` and `U^(233)` Only fissile MATERIALS are used in fuel of nuclear reactor. | |
| 4529. |
What are the qualities of an ideal source of energy ? |
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Answer» Solution :An ideal source of energy has following qualities. (i) It gives us more heat PER unit mass. (II) It does not pollute the air on burning by giving out smoke or harmful gases . (iii) It should be CHEAP and easily available. (iv) It should be easy to handle , SAFE to TRANSPORT . |
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| 4530. |
What does the magnetic field pattern inside the solenoid indicate ? State how this field be utilised to make an electromagnet. List two ways by whi.ch strength of this magnet can be increased. |
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Answer» Solution :It Indicates that the magnetic field is same at all points INSIDE the solenoid. This property is utilised to magnetise a piece of magnetic MATERIAL LIKE soft IRON when placed inside the coil. Two ways by which strength of electromagnet can be increased : lncreasing the amount of electric current through it. Increasing the number of turns of the coil. |
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| 4531. |
Explain the effect on the magnetic field produced at a point in a current carrying circularcoil due to : (i) increase in the amount of current flowing through it. (ii) increasein the distance of point from the coil (iii) increase in the number of turns of the coil. |
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Answer» Solution :(i) The magnitude of MAGNETIC field produced by a current carrying circular coil at a point is directly proportional to the current flowing through the circular coil . Thus as the amountof current flowing through the circular coil INCREASES, the magnetic field produced at a point in a circular coil increases. (ii) Magnetude of magnetic field producedat a point in a current carrying circular coil is inversely proportional to the distance of point from the coil. Thus the magnetic field produced at a point decreases as the distance increases from the coil. (iii) The magnetic field produced by a current carrying WIRE at a given point depends directly on the current passing through it. Therefore, if there is a circular coil having n TURNS, the field produced in n times as that produced by a single turn. This is becausethe current in each circular turn has the same direction, and the field due to such turns then just ADDS up . |
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| 4532. |
State-Avogardo's law. |
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Answer» Solution :Avogardo's law states that at CONSTANT pressure and TEMPERATURE, the volume of GAS is directly proportional to number of atoms or MOLECULES in it. (i.e)`V prop n` (or) `(V)/(n)`= constant |
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| 4533. |
The radius of curvature of a convex mirror is 24 cm. What is its focal length? |
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Answer» 24 |
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| 4534. |
Name the device which converts electrical energy into mechanical energy. |
| Answer» SOLUTION :ELECTRIC MOTOR | |
| 4535. |
What happens to resistance of a conductor if area of cross section is doubled? |
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Answer» SOLUTION :The resistance of a CONDUCTOR is inversely proportional to its AREA of CROSS section. `RpropI/A` If A is changed to 2A, `R=I/(2A)` i.e., Resistance will be REDUCED to half. |
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| 4536. |
The amount of force required for a body of mass 1 gram produces an accelaretion of 1 cm s^(2) |
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| 4537. |
a. Define ocal length of a divergent lens. b. A divergetn lens of focal length 30 cm forms the image of an object of size 6 cm on the same side as the object at a distance of 15 cm from its optical centre. Use lens formula to determine the distance of the object the lens and the size of the image formed. |
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Answer» SOLUTION :a. The distance between the principal focus and the optical CENTRES of the concave lens or diverging lens is called the FOCAL length of a diverging lens. b. `f=-30cm` `h=6cm` `v=15cm, u=?,h=?`  Lens formula: `1/v-1/u=1/f` or `(-1)/u=1/f-1/v` `(-1)/15-1/u=(-1)/30` or `(-1)/u=(-1)/30-((-1)/15)` `(-1)/u=(-1)/30+1/15` `(-1)/u=(-15+30)/450` `(-1)/u=1/30` `=u=30` `u=-30cm` The object distance is -30 cm. `m=v/u=(h^(1))/h` `(+15)/(+30)=(h^(1))/6` or `6/2=h^(1)` `h^(1)=3 cm` The height of the image is 3 cm. |
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| 4538. |
Compare the power used in the 2Omega resistor in each of the following circuits: a 4 V battery in parallel with 12 Omega and 2Omega resistors |
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Answer» Solution :As `12 Omega` resistor and `2Omega` resistor are connected in PARALLEL and 4 V battery is connected in parallel with this parallel combination of resistors, The p.d. across `2Omega` resistor will also be 4 V. `:.` Power USED in `2Omega` resistor. `P_2 = V^2/R = 4^2/2 =16/2 =8 W` In order to compare the power used in `2 Omega` resistor in two DIFFERENT circuits, find the ratio of `P_1 and P_2`. So, `P_1/P_2=8/8 =1 :. P_1 = P_2` HENCE `2Omega` resistor uses equal power, i.e., 8 W in both the circuits. |
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| 4539. |
Equal heat is given to two objects X and Y of equal mass. Temperature of X increases by6^(@)Cand Y by4.5^(@)C . Which object has more specific heat? And by what factor? |
| Answer» SOLUTION :`Y, 4/3` | |
| 4540. |
Liquor, Beer, Wine, Juice. |
| Answer» SOLUTION :JUICE as other are not GOOD for HEALTH while, juice HELPS for good health. | |
| 4541. |
A satellite orbits the earth at a height 'R' from the surface. How much energy must be expended to rocket the satellite out of earth's gravitational influence? |
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Answer» SOLUTION :The energy required to pull the satellite from earth influence should be EQUAL to the total energy with which it is revolving around the earth The K.E. of satellite `=(1)/(2)mv^(2)= (1)/(2)m (GM)/(R+h), "" v= sqrt((GM)/(R+h))` The P.E. of satellite `= -(GMm)/(R+h)` `T.E.= (1)/(2)(MGM)/(2(R+h))-(GMm)/((R+h))=(1)/(2)(GMm)/((R+h))` Energy required will be `(+(1)/(4)(GMm)/((R)))`. |
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| 4542. |
What is meant by Scattering of light ? |
| Answer» SOLUTION :When sunlight enters the earth's atmosphere , the ATOMS and molecules of different GASES present in the atmosphere REFRACT the light in all possible directions. This is called as 'Scattering of light'. | |
| 4543. |
What is meant by Weightlessness ? |
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Answer» Solution :When the person in a LIFT MOVES down with an acceleration (a) equal to the acceleration DUE to gravity ( g) , i.e., when a =g , this motion is calledas ' free wall ' . Here , the apparent WEIGHT (R=m(g-g)=0) of the person is zero . |
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| 4544. |
Find the heat needed to raise the temperature of a piece of iron of mass 500 g by 40^(@)C . ( c = 0.110 cal//g.^(@)C ) |
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| 4545. |
A child sitting at the back bench of a classroom is unable to see the letters on the board clearly. What is the defect of the eye of the child? How can it be remedied? Draw its ray diagram. |
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| 4547. |
A personneedsa lensof power-5.5dioptres forcorrectinghisdistantvision.Forcorrectinghis nearvision,he needsa lensof power+ 1.5dioptres. What is thefocallengthof therequiredforcorrecting(i)distant vision, and (ii)nearvision ? |
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Answer» Solution :(i)fordistant VISION: Powerof LENS ,P=-5.5D Now ,Power , `P=(1)/(f"(in metres)")""("where f=Focal length ")` SO, `-5.5=(1)/(f)` And , `f=(1)/(-5.5)m` Or , `f=-(1)/(5.5)xx100cm` So, Focal length f=-18.18 CM `""`(or-18.2cm) thusthe focal lengthof lens requiredforcorrecingdistant visionis, - 18.2 cm. Minus signof focallengthtells us that it is a concave lens. (ii)fornearvision: power of lens, P=+ 1.5D Now, Power, `P=(1)/(f"(metres)") ` So `+1.5 =(1)/(f)` And `f=(1)/(+1.5)m` Or, `f = +(1)/(1.5)xx100cm` So,focal length, f = + 66.66 cm(or + 66.7 cm) Thusthe FOCALLENGTH of lensrequiredforrequiredfor correctingnearvisionis +66.7 cmPlussign of focallength tellsus thatit isa convex lens. |
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| 4548. |
How far away from the surface of earth does the acceleration due to gravity become 36% of its value on the surface of earth? Radius of earth =6400km. |
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Answer» SOLUTION :`g'=36%" of "g= (36)/(100)g` `(36)/(100)g= g[(R )/(R+h)]^(2)` `(6)/(10)=(R)/(R+h)` `h=4/6R= 4267 km`. |
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| 4549. |
State whether the moment of force is a scalar or vector quantity. |
| Answer» SOLUTION :VECTOR QUANTITY | |
| 4550. |
Compare the power used in the 2Omega resistors in each of th following circuits : (i) a 6V battery in series with 1Omega and 2Omega resistor, and (ii) a 4 V battery in parallel with 12Omega and 2Omega resistors. |
Answer» Solution :Case [i]  Current in the circuit, `I=V/(R_(1)+R_(2))=6/3=2A` POWER used = `I^(2)R=(2)^(2)xx2=2xx2xx2=8W` `R=1+2=3Omega` `I=V/R=6/3=2A` Therefore VOLTAGE across `2OMEGA` resistor = `1xx2=2xx2=4V` `PI=VI=4xx2=8W` Case [ii] `I_(2)=V/R_(2)=4/2=2A` `P_(2)` across `2Omega` resistor = `4xx2=8W` Therefore RATIO, `P_(1):P_(2)=8:8=1` 
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