InterviewSolution
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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.
| 2602. |
Blood circulation in fishes is different from the blood circulation in human beings." Justify the statement(b) Describe "blood circulation" in human beings. |
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Answer» Solution : Fishes have two-chambered heart - one ventricle and one auricle. The blood is pumped into gills where it is oxygenated and supplied directly to body parts from gills. Thus, blood goes only once through the heart. (b) Double CIRCULATION is the passage of the same blood twice through the heart, first on the right side then on the left side in order to complete one cycle. Double circulation has two components: Pulmonary circulation and systemic circulation. Pulmonary circulation - It is the movement of blood from heart to the lungs and back. DEOXYGENATED blood of the body enters the right auricle, passes into RIGHTS ventricle which pumps it into pulmonary arch. With the help of two separate pulmonary arteries the blood passes into the lungs. Here the arteries break up into arterioles and then capillaries for oxygenation. Capllaries join to form venules and then veins. Oxygenated blood comes back to the left auricle of heart through pulmonary veins. Systemic circulation – It is the circulation of blood between heart and DIFFERENT parts of the body except lungs. Oxygenated blood received by left auricle passes into left ventricle. The left ventricle pumps it into aorta for supply to different body parts. Inside the organs the arteries break up into arterioles and then capillaries. Capillaries provide oxygen and nutrients to tissues. Capillaries unite to form venules which join to produce veins. Veins take the deoxygenated blood to the heart but now into the right auricle. Significance of double circulation - It ensures quick and efficient supply of oxygenated blood to all body parts for MEETING higher energy needs and for thermoregulation of body in mammals and birds. 
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| 2603. |
Two balls of different masses are thrown vertically upward with same initial velocity.Height attained by them are h_1 and h_2 respectively. What is h_1//h_2 ? |
| Answer» SOLUTION :Same HEIGHT, `thereforeh_(1)//h_(2)=1` | |
| 2604. |
State the laws of refraction of light. If the speedof light in vacuum is 3xx10^(8) m/s, find the absolute refractive index of a medium in which light travels with a speed of 1.4xx10^(8) ms? |
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Answer» Solution :(i) There are two laws of refraction a. The RATIO fo the sine of the angle of incidence to the sine of the angle of refractive is constant. This is known as Snell.s law. Mathematicaly, it can be expressed as `sini//sin r=n_(12)` Here `n_(12)` is the relative refractive INDEX of medium 1 with respect to medium 2. b. The incident ray, the refracted ray and the normal to the interface of two media at the point of incidence lie on the same plane. (ii) Give `c=3xx10^(8)m//s` `v=1.4xx10^(8)m//s` Absolute refractive index `=("Speed of LIGHT in vacuum")/("Speed of light in medium")` `=(3xx10^(8)m//s)/(1.4xx10^(8)m//s)=2.14` |
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| 2605. |
What steps are included in the post -disaster management plan? |
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Answer» Solution :i. The post disaster management plan includes the VARIOUS measures taken to reduce the DESTRUCTIVE effects of the disaster and bringing normalcy in the area where the disaster has OCCURRED. ii. The various factors considred in this plan are as follows : a. PROVIDING help to the victims of disasters, in all possible ways. b. Arranging help to the victims of the disaster with the help of local people who were not harmed by the disaster. c. Quick establishment of control and help centres depending upon the type of disaster. d. Categorization and delivery of relief materials obained from control centres, and continuous review of the same. e. Being ALERT and prepared for disaster rescue. |
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| 2606. |
Whatis an electricgenerator ? |
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Answer» SOLUTION :Anelectricgenerator is a deviceused to CONVERT MECHANICAL energyintoelectricalenergy . Anelectricgenerator is an APPLICATIONOF electromagenticinduction . |
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| 2607. |
Ionising power of the gamma rays |
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Answer» COMPARATIVELY very HIGH ionization power |
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| 2608. |
a) What is thermite reaction ? b) Q is an element which is one in copper, zinc, aluminium and iron, its properties are as follows. i) Q_(2)Q_(3) is found in nature but not affected by water. ii) Two chlorides with formula QCI_(2) and QCI_(3) are formed by the metal. Identify the metal |
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Answer» Solution : a) The displacement REACTION which is highly exothermic and the metal produced is in molten STATE is called thermite reaction. i). Since the OXIDE of the metal is `Q_(2)Q_(3)` its valence is 3. therefore out of the MENTIONED metal only adumimium and iron can be the metal with properties mentioned above. ii) `QCI_(2)` and `QCI_(3)` must be iron as it shows varible valency of two and three. `FeCl_(2)` and `FeCl_(3)` are the chlorides. |
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| 2609. |
For the same angle of incidence of 45^(@), the refraction angle in three transparent media A, B and C are 25^(@), 30^(@) and 35^(@), respectively. In which medium is the speed of light minimum and in which mediym maximum ? |
| Answer» SOLUTION :SPEED of light is MINIMUM in MEDIUM A and MAXIMUM in medium C. | |
| 2610. |
An electric motor is a device employed to transforms electrical energy into mechanical energy. |
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| 2611. |
The radius of curvature of a spherical mirror is 20 cm. What is the focal length? |
| Answer» SOLUTION :`f=R/2=20/2=10cm` | |
| 2612. |
Which of the followingcorrectlydescribles the magnetic field neara longstraight wire ? |
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Answer» The FIELD consitsof STRAIGHT lines perpendicular to the wire . |
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| 2613. |
Compare and contrast fossil fuels and the Sun as direct sources of energy . |
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Answer» SOLUTION :(i) The reserves of fossil are limited, i.e., exhaustiblewhereas solar energy is available in abundance (and that too without COST) i.e., inexhaustible. (ii) Fossils fuels cause pollution on BURNING whereas solar energy in pollution - free. (iii) Fossil fuels can provide energy at any required time whereas solar energy becomes unavailable when the sky is covered with CLOUDS. |
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| 2614. |
What is the role of the earth wire in domestic circuits ? |
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Answer» Solution :(i) The earth WIRE PROVIDES a LOW resistance path to the electric current . (ii) The earth wire sends the current from the body of the appliance to the Earth, wherever a live wire accidentally TOUCHES the body of the metallic electric appliance. (iii) Thus, the earth wire serves as a protechtive, which saves US from electric shocks. |
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| 2615. |
State important characteristics of magnetic force experienced by charge moving in a magnetic field (or a current-carrying conductor placed in a magnetic field). |
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Answer» Solution :IMPORTANT characteristics of magnetic force are as given below: (i) Magnetic force ACTS only on moving charges (or flowing current) and does not act on stationary charges. (ii) Force acts on moving CHARGE when its motion is not parallel to the direction of magnetic field. Similarly, magnetic force acts when current-carrying conductor is in any direction other than the direction of magnetic field. (iii) Magnitude of magnetic force is maximum when current-carrying conductor is set perpendicular to magnetic field or when charge is moving at RIGHT angle to magnetic field. (iv) The direction of force F is given by Fleming.s left-hand rule. (v) The magnitude of magnetic force depends UPON (a) the amount of current I, (b) the magnetic field B, and (c) the length of the conductor I. On increasing anyone or all of these factors force increases proportionately. |
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| 2616. |
The resistance of 300 m long wire with cross-sectional area 10^(-6)m^2 and resistivity 10^(-7) Omegam is …………… . |
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Answer» `30 Omega` `= 10^(-7) xx 300/(10^(-6))` `=30 Omega` |
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| 2617. |
Your friend can read a book perfectly well but cannot read the writing on blackboard unless she sits on the front row in class. (a) Is she short-sighted or long-sighted ? (b) What type of lenses-convergingor diverging-would an optician prescribe for her ? |
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| 2618. |
Whydoesthe reactionrateof areactionincrease onraisingthe temperature ? |
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Answer» Solution :On increasing temperature heat is supplied to the reactant. This energy breaks more bonds and THUS speed up the chemical reaction. Foods kept at room temperature spoils faster than that kept in the refrigerator. (b) There are two major classes of double displacement reactions. They are, (i) Precipitation Reactions When aqueous solutions of two compounds are mixed, if they react to form an insoluble compound and a soluble compound, then it is CALLED precipitation reaction. `Pb(NO_(3))_(2(aq))+2KI_((aq))toPbI_(2(s))darr+2KNO_(3(aq))` (ii) Neutralisation Reactions Another type of displacement reaction in which the ACID reacts with the base to form a salt and WATER. It is called .neutralisation reaction. as both acid and base neutralize each other. `NaOH_((aq))+HCl_((aq))toNaCl_((aq))+H_(2)O_((1))` |
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| 2619. |
Several electric bulbs designed to be used on a 220V electric supply line, are rated 10W. How many lamps can be connected in parallel with each other across the two wires of 220V line if the maximum allowable current is 5A? |
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Answer» Solution :As each BULB is rated as 10W,220V it DRAWS a CURRENT. `I=P/V=(10W)/(220V)=1/22A` As the maximum allowable current is `I_(max)=A` and all lamps are connected in parallel, hence,maximum number of bulbs joined in parallel with each other. `n=(I_(max))/I=(5A)/(1/22A)= 5 times 22=110` |
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| 2620. |
The colour of the sun is red at sun is red at sunrise and sunset . This occurs due to …… |
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Answer» Rayleigh |
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| 2621. |
(a) List the difference between RBC and WBC. (b) Define triple fusion. |
| Answer» Solution :The fusion involving TWO polar nucleus and a sperm nucleus, that occurs in double fertilization in a SEED plant and RESULTS in the formation ofendosperm is CALLED the triple fusion. | |
| 2622. |
In Fleming's right hand rule-Thumb : Motion of conductor :: In Fleming's right hand rule-Index finger : _____________ |
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Answer» Solution :Magnetic field In Fleming's RIGHT hand rule, THUMB represents DIRECTION of motion of CONDUCTOR and index FINGER represents the direction of magnetic field. |
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| 2623. |
Calculate the resistivity of a material of a wire 10 m long. 0.4 mm in diameter and having a resistance of 2.0Omega. |
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Answer» Solution :`L=10m" , "d=0.4mm=0.4xx10^(-3)m` `r=0.2xx10^(-3)m` `R=20Omega` Resistivity (or) specific resistance of a material `RHO=(RA)/(l)=(Rxxpir^(2))/(l)` `=(20xx3.14xx(0.2xx10^(-3))^(2))/(10)` `=6.28xx0.04xx10^(-6)` `rho=2.513xx10^(-8)OMEGAM` |
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| 2624. |
A mountainer climbing on the Everst, experienced the following facts. Explain each fact with the scientific reason :(1) He found fishes alive below the ice (2) Time required for cooking was more as he went higher (3) He saw many cliffs falling suddenly ( 4) He saw tubes carrying water broken. |
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Answer» Solution :Explanation `:` (1) WATER expands as its temperature DECREASES from `4^(@)C ` to `0^(@)C `. Water is converted into ice at `0^(@)C ` . The density of water is more than that of ice .Fishes can remain alive in the water (at `4^(@) C )` below that ice. (2) At high altitude, ATMOSPHERIC pressure is low and hence water boils at a temperature lower than its normal boiling point. Therefore, the time required for cooking food is more higher altitudes. (3) Water expands while freezing. Hence, the water PRESENT in the crevices of the rocks EXERTS a tramendous pressure on the rocks, while freezing .Therefore, the cliffs falls. (4) Water expands while freezing. Hence, the water in the tube exerts a large pressure on the tube, while freezing .Therefore, the tube carrying water breaks. |
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| 2625. |
What is an echo? (a) State two conditions necessary for hearing an echo. (b) What are the medical applications of echo? c) How can you calculate the speed of sound using echo? |
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Answer» Solution :Echo: An echo is the sound reproduced due to the rigid surfaces such as walls, CEILINGS, surfaces of mountains, etc. (a) (i) The persistence of hearing for human ears is 0.1 second. This means that we can hear two sound waves clearly, if the time interval between the two sounds is atleast 0.1 s. Thus, the minimum time GAP between the original sound and an echo must be 0.1s (ii) The above criterion can be satisfied only when the distance between the SOURCE of sound and the reflecting surface would satisfy the following equation: Velocity `("Distance travelled by sound")/("Time taken")` `v=(2d)/(t)` `d=(vt)/(2)` Since, t=0.1 second, then `d=(vxx0.1)/(2)=(v)/(20)` (b) (i) The principle of echo is used in obstetric ultrasonography, which is used to create real-time visual images of the developing embryo or fetus in the mother.s uterus. (ii) This is a safe testing tool, as it does not use any harmful radiations. (c) Apparatus required: A source of sound pulses, a measuring TAPE, a sound receiver and a stop watch. Calculation of speed of sound: The sound pulse emitted by the source travels a total distance of 2d while travelling from the source to the wall and then back to the receiver. The time taken for this has been observed to be .t.. Hence, the speed of sound wave is given by Speed of sound `=("Distance travelled")/("Time taken")=(2d)/(t)` |
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| 2626. |
A hollow cylinder has a charge q coulomb within it. If phi is the electric flux is unit of volt -m associated with the curved surface B, the flux linked with the plane surface A in the same units will be |
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Answer» `(phi)/(3)` |
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| 2627. |
Three resistors of resistances R_1, R_2 and R_3 are connected in (i) series and (ii) parallel. Write expression for the equivalent resistance of the combination in each case. (b) Two identical resistance of 12 Omega each are connected to a battery of 3V. Calculate the ratio of the power consumed by the resulting combinations with minimum resistance and maximum resistance. |
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Answer» Solution :(i) In SERIES arrangement equivalent resistance `R_s=R_1+R_2+R_3` (ii) In parallel arrangement equivalent resistance `R_p` is GIVEN as: `1/R_p=1/R_1+1/R_2+1/R_3` (B) Here `R_1=R_2=12 Omega and V=3V` For minimum resistance, two RESISTORS must be connected in parallel so that `1/R_p=1/R_1+1/R_2=1/12+1/12=1/6 implies R_p=6 Omega` Hence power `P_p=V^2/R_p=(3)^2/6=1.5W` For maximum resistance two resistors must be connected in series so that `R_s=R_1+R_2=12+12=24 Omega` So the power, `P_s=V^2/R_s=(3)^2/24=0.375W implies P_p/P_s=1.5/0.375=4/1` |
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| 2628. |
State whether the following statements are true of false. A wire with a green insulation is usually the live wire. |
| Answer» Solution :False: An WIRE a green INSULATION is usually the EARTH wire. | |
| 2629. |
Calculate the power of convex lens of focal length 15 cm. |
| Answer» SOLUTION :`+6.7 D` | |
| 2630. |
Whatis electromagneticinduction ? |
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Answer» Solution :Theprocess , by whicha changingmagnetic fieldin a conductor induces a currentin anotherconductoris called ELECTROMAGNETICINDUCTION . OR An ELECTRIC currentproduced in a closedcircuitproduced in a closedcircuitby a changingmagnetic FIELD is calledan INDUCED current . This phenomenon is called electromagneticinduction . |
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| 2631. |
I am diploblastic and acoelomate. Which phylum do I belong to ? |
| Answer» SOLUTION :I am from PHYLUM CNIDARIA or Coeleterata. | |
| 2632. |
In S=a+bt+ct^(2).S is measured in metres and t in seconds. The unit of c is |
| Answer» SOLUTION :The unit of left hand SIDE is METRE so the UNITS of `ct^(2)` should also be metre. Since `t^(2)` has unit of `s^(2)`, so the unit of c is `m/s^(2)`. | |
| 2633. |
Explain the 'ten percent law' for the flow, of energy, through a food chain. Why do we say that the flow of energy through the food chains is unidirectional ? |
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Answer» Solution :According to the ten percent law, `90%` of the energy from the PREVIOUS trophic LEVEL is lost as heat to the environment. Only `10%` of the energy in the form of FOOD energy, present within the first trophic level FLOWS ot the second trophic level and in the same way from second trophic level to the third level and so on. The energy, in the form of food always from first trophic level to the last trophic level of a food chain. It never flows back from the last trophic level to the last trophic of a food chain. It never flows back from the last trophic level to the first trophic level, so we say that the FLOW of energy is unidirectional through the food chains. |
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| 2634. |
What is geothermal energy ? How can it be used commercially ? List in tabular form three distinguishing features between a thermal power plant and a geothermal power plant. |
Answer» SOLUTION :It can be USED to PRODUCE ELECTRICITY. 
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| 2635. |
Assertion (A) : SI unit of refractive index is m s^(-1) Reason (R) : Glass is said to be optically denser thn kerosene because optical density of glass is greater than that of kerosene. |
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Answer» Both (A) and (R) are true and (R) is correct explanation of the ASSERTION. |
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| 2636. |
The right-hand thumprule was stated by |
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Answer» Oersted |
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| 2637. |
The IUPAC name of an organic compound is 3-Methyl butan-1-ol. What type compound it is ? |
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Answer» Aldehyde |
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| 2638. |
0.0014kg of nitrogen is enclosed in a vessel at a temperature of 27^(@)C. How much heat has to be transferred to the gas to double the rms speed of its molecules. |
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Answer» Solution :Number of mole in `0.014kg` of Nitrogen `n=(0.0014xx10^(3))/(28)=(1)/(20)` mole `C_(v)=(5)/(2)R=(5)/(2)xx2=5` cal/mole `k` `(V_(2))/(V_(1))=sqrt((T_(2))/(T_(1)))`, `T_(2)=4T_(1)` `DeltaT=T_(2)-T_(1)=4T_(1)-T_(1)=3T_(1)` `=3xx300=900K` `DeltaQ=nc_(v)DeltaT=(1)/(20)xx5xx900=225cal` |
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| 2639. |
A thin conducting ring of radius R is given a charge +Q, Fig. The electric field at the center O of the ring due to the charge on the part AKB of the ring is E. The electric field at the center due to the charge on part ACDB of the ring is |
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Answer» `3 E` along `KO` |
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| 2640. |
According to Boyle's law, PV = constant, at constant temperature. Which of the following graphs is correct? |
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Answer»
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| 2641. |
Show the path of a refracted ray formed on refraction through a spherical lens, when (i) incident ray is parallel to the principal axis of lens, (ii) incident ray passes through principal focus (or is directed towards the principal focus) of lens. Draw ray diagrams too. |
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Answer» SOLUTION :(i) As SHOWN in figure, an incident ray coming parallel to the principal axis of convex lens, after refraction, passes through its principal focus `F_(2)`, on the other side of lens. In case of a concave lens, as shown in Figure, the refracted ray appears to DIVERGE from the principal focus `F_(1)` locaed on the same side of lens. (ii) For a convex lens, a light ray passing through its principal focus `F_(1)` will emerge parallel to the principal axis after refraction. In case of a concave lens, a light ray appearing to meet at principal focus `F_(2)` will emerge parallel to the principal axis after refraction. 
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| 2642. |
(a) What is a solenoid ? Draw the pattern of magnetic field lines of a solenoid through which a steady current flows. (b) Mention two ways to increase the strength of the magnetic field of a solenoid. |
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Answer» SOLUTION :(a) See Short Answer QUESTION Number 12. (b) The strength of magnetic field of a SOLENOID can be increased by (1) increasing the current flowing through solenoid coil, and (ii) increasing the number of TURNS per unit length of the solenoid coil. |
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| 2643. |
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes ? |
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Answer» Solution :An electric generator works on the pnneipe of electromagnetic induction. 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: When the AXLE attached to the two rings is rotated such that the arm AB moves up (and the arm CD moves down) in the magnetic filed produced by the permanent magnet. The coil ABCD is rotated CLOCKWISE in the arrangement. By applying Fleming.s ight-hand rule, the induced Currents are set up in these arms along the directions AB and CD. Thus an induced current flows in the direction ABCD. If there are LARGER numbers of turns in the coil, the current generated in each tum adds up to give a large current through the coil. This means that the current in the external circuit flows from B2 to B1. After half a rotation, arm CD STARTS moving up and AB moving down. As a result, the directions of the induced currents in both the arms change, giving rise to the net induced current in the direction DCBA. The current in the external circuit now flows from B1 to B2. Thus after every half rotation the polarity of the currentin the respective arms changes. Such a current, which changes direction after equal intervals of time, is called an ALTERNATING current (abbreviated as AC). This device is called an AC generator Function of brushes: it helps in transferring current from the coil ABCD to the externa circuit . 
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| 2644. |
Whatis a galvanometer ? |
| Answer» Solution :A galvanometeris an INSTRUMENT USED to detec the PRESENCE of an electriccurrent in a CIRCUIT. | |
| 2645. |
How many 176 Omega resistor (in parallel) are requried to carry 5A on a 220V line? |
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Answer» SOLUTION :Let n RESISTORS of `176 Omega` are joined in parallel. Then their combined resistances `R_p` is GIVEN by `1/R_p=1/176+1/176….n time s=n/176 or R_p=176/n Omega` It is given that V=220V and I=5A `therefore R_p=V/I or 176/n=220/5=44` `IMPLIES n=176/44=4 i.e., 4` resistors should be joined in parallel. |
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| 2646. |
Whichinstrumentis used to convert electrical energy intomechanical energy ? |
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Answer» ELECTRIC GENERATOR |
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| 2647. |
Which part of Sun's energy is responsible for drying clothes and exposure to which part could be a health hazard? |
| Answer» SOLUTION :Infra - red (IR) radiations are responsible for drying clothes and ULTRAVIOLET (UV) radiations COULD be a HEALTH hazard. | |
| 2648. |
State and prove the law of conservation of linear momentum. |
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Answer» Solution :(i) There is no change in the linear momentum fo a system of bodies as long as no net external force acts on them. (ii) Let us prove the law of conservation of linear momentum with the following illustration:  (iii) Let two bodies A and B having masses `m_(1) and m_(2)` MOVE with initial velocity `u_(1) and u_(2)` in a straight line. (iv) Let the velocity of the FIRST body be higher than that of the second body. i.e., `u_(1) gt u_(2)`. (v) During an interval of time t second, they tend to have a collision. After the impact, both of them move along the same straight line with a velocity `v_(1) and v_(2)` respectively. Force on body B due to A, `F_(B)=(m_(2)[v_(2)-u_(2)])/(t)` Force on body A due to B, `F_(A)=(m_(1)[v_(1)-u_(1)])/(t)` By Netwon.s III law of motion, Action force = Reaction force `F_(A)=-F_(B)` `(m_(1)[v_(1)-u_(1)])/(t)=(m_(2)[v_(2)-u_(2)])/(t)` `m_(1)v_(1)+m_(2)v_(2)=m_(1)u_(1)+m_(2)u_(2)` The above equation confirms in the absence of an external force, the algebraic SUM of the momentum after collision is numerically EQUAL to the algebraic sum of the momentum before collision. Hence the law of conservation linear momentum is proved. |
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| 2649. |
What is biogas ? Why is biogas considered an ideal fuel for domestic use ? |
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Answer» Solution :Biogas is a combustible mixture of methane (about 75%) , CARBON dioxide, hydrogen and hydrogen sulphide gas . It is obtained by anaerobic DECOMPOSITION of human and animal excrete and AGRICULTURAL and urban waste materials. Biogas is considered an ideal fuel for domestic use because of the FOLLOWING reasons: (i) It has high calorific value . (ii) It does not produce smoke. |
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| 2650. |
Name the phenomenon associated with the following: (i) The sky appear blue. (ii) Formation of a rainbow in the sky. (iii) Twinkling of stars. |
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Answer» Solution :(i) (a) Atmospheric refraction (b) Scattering of light (ii) (a) DISPERSION (b) Refraction (c) Total internal REFLECTION (iii) (a) Atmospheric refraction (b) Change in the DENSITY of the atmosphere due to TEMPERATURE and other CONDITIONS. |
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