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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.
| 8951. |
Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the 40 W bulb will be : |
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Answer» 0.4 A [HINT : In SERIES CIRCUIT same CURRENT flows through all the circuit ELEMENTS] |
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| 8952. |
At the time of short-circuit, the current in the circuit |
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Answer» REDUCES SUBSTANTIALLY |
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| 8953. |
What are the advantage of solar panel? |
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Answer» SOLUTION :• LOW cost maintenance • Have no moving parts . • Can work efficiently without any aid of FOCUSING DEVICE. • Can be set up in REMOTE and in accessible hamlets or very sparsely inhabited areas • Provide pollution free, noiseless energy |
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| 8954. |
State two reason for the following facts (i) Sulphur is a non metal (ii) megnesium is a metal |
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Answer» SOLUTION :(i) a) POOR conductor of heat and electricity b) `S + O_2 to SO_2 `SO_2 + H_2O to H_2SO_3` Sulphurdioxide is acidic oxide . II) a) Good conductor of heat and electric b) `2Mg + O_2 to 2Mg O` `MgO + H_2O to Mg(OH)_2` Magnesium oxide in nature . |
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| 8955. |
Conserving energy has become the need of the society and nature, be it in the transport, house hold or industries. Energy conservation has been recognized as a national issue for long time. As a responsible citizen of India, what steps would you take to conserve energy ? |
| Answer» Solution :Use of renewable SOURCES of energy-Population CONTROL, Planting TREES (AFFORESTATION) | |
| 8956. |
Solid sodium bicarbonate was placed on a strip of pH paper. What was the change in colour ? |
| Answer» Solution :The colour of the PH PAPER did not CHANGE because pH paper shows colour depending on the hydrogen ion concentration in solution. Soild sodium bicarbonate does not produce hydrogen ions in its solid state THUS does not GIVEN any colour on pH paper. | |
| 8957. |
A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the objec ? Also, find the power of the lens. |
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Answer» Solution :As REAL and INVERTED IMAGE of a needle is formed by convex LENS at a distance of 50 cm from it, hence `upsilon = +50` cm. As size of image = size of object, hence h. = h. But `(h.)/(h) = (upsilon)/(u)` `rArr""u = (upsilon h)/(h.) = (50 XX h)/(h) = 50` cm So, the needle is placed 50 cm in front of convex lens as per sign convention u = -50 cm. Now `(1)(v) - (1)/(u) = (1)/(f)` `therefore""(1)/(f) = (1)/((50)) - (1)/((-50)) = (1)/(50) + (1)/(50) = (1)/(25)` cm `rArr""f` = +25 cm = +0.25 m `therefore` Power of the lens `P = (1)/(f(m)) = (1)/(0.25 m) = +4D` |
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| 8958. |
What is power of accomodation of eye? |
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Answer» Solution :(i) The ability of the eye lens to focus nearby as well as the DISTANT OBJECTS is CALLED power of accommodation of the eye. (ii) Thisis achieved by changing the focal length of the eye lens with help of CILIARY MUSCLES. |
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| 8959. |
The refractive index of the second medium with respect to thefirst medium is given by the ratio v_(2)//v_(1). |
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Answer» |
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| 8960. |
In order to determine the focal length of a concave mirror, a student obtained a sharp image of the grill of a window in the laboratory wall on a screen. His teacher suggested that to get better result for focal length, he should focus a distant tree instead of the window grill. In which direction should the mirror be moved for for this purpose so as to get a sharp image of the tree on the screen ? |
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Answer» BEHIND the screen |
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| 8962. |
The numerical ratio of displacement to distance for a moving object is : |
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Answer» ALWAYS LESS than 1 |
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| 8963. |
A fixed wire AB carries current I. An electron is moving parallel to the wire, in which direction does the electron tend to move? |
Answer» Solution : By right-hand thumb rule, the MAGNETIC field in the vicinity of WIRE is downward perpendicular to plane of paper. The conventional direction of electric current is opposite to the direction of motion of electron. By Fleming.s left-hand rule, the FORCE on electron is away from wire in the plane of paper, THEREFORE, the electron will be deflected downward (away from wire) in the plane of paper. |
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| 8964. |
Give the function of control rods in a nuclear reactor. |
| Answer» SOLUTION :Control rods are used to control the NUMBER of neutrons in order to have sustained chain REACTION. Mostly boron or CADMIUM rods are used as control rods. They absorb the neutrons. | |
| 8965. |
The centromere is found at the centre of the ______ chromosome. |
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Answer» TELOCENTRIC |
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| 8966. |
Crosses otimesrepresent a unilorm magnetic field dincted into the paper. A conductor XY moves in the field toward right side. Find the direction of induced current in the conductor. Name the rule you applied. What will be the direction of current if the direction of field and the direction of motion of the conductor both are revened ? |
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Answer» Solution :(i) Y to X (II) Fleming.s right hand RULE. (iii) The direction of indcued CURRENT will STILL be the same i.e. Y to X. |
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| 8967. |
What is the direction of the magneticforceactingon a current - carryingwire placed in a magnetic field ? |
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Answer» ALONGTHE magneticfield |
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| 8968. |
A material medium X has a refractive index 1.5 and another medium Y has a refractive index of 1.44.(a) Calculate the velocity of light in each of these media.(b) In which medium will travel faster ? |
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Answer» Solution :`{:("MEDIUM X","Medium Y"),(mu_(x)=1.5,mu_(y)=1.44),(mu_(X)=(c )/(V_(X)),mu_(X)=(c )/(V_(x))),(V_(x)=(c )/(mu_(x))=(3xx10^(8))/(1.5),v_(y)=(c )/(mu_(y))=(3xx10^(8))/(1.44)),(=2xx10^(8)m//s,=2.08xx10^(8)m//s):}` (B) Light will travel FASTER in medium Y when compared to medium X. |
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| 8969. |
How much longer is a parsec from a light year? |
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Answer» 3.56 times |
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| 8972. |
A 50 g bullet is fired from a 10 kg gun with a speed of 500 ms^(-1). What is the speed of the recoil of the gun. |
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Answer» Solution :INITIAL MOMENTUM =0 using conservation of linear momentum `MV+MV=0` `V=(-mv)/(M)` `rArr V=2.5m//s` |
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| 8973. |
What is nichrome? State its one use. |
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Answer» Solution :NICHROME is an alloy of NICKEL [60%], CHROMIUM [12%], Manganese [2%] and Iron [26%]. Specific use: It has high melting point as well as high resistivity. So used in electric irons, toaster geysers etc. Nichrome is used in the explosives and fireworks industry as a bridge wire in electric ignition systems, such as electric matches and MODEL rocket igniters. |
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| 8974. |
Hydrogen gas has high calorific value but it is not used as a domestic fuel. Why ? |
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Answer» Solution :Though hydrogen has high CALORIFIC VALUE yet it is not used as a domestic fuel because of the following REASONS : 1. It is HIGHLY combustible gas and its combustion cannot be controlled. 2. Its transportation is difficult. 3. Its cost of production is high. |
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| 8975. |
Find out the following in the electric circuit given in the figure. (i) Effective resistance of two 8 Omega resistors In the combination (ii) Current flowing through 4 Omega resistor (iii) Potential difference across 4Omega resistor (iv) Power dissipated in 4Omega resistor (v) Difference in reading of ammeter A_(1) and A_(2) ( if any) . |
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Answer» <P> Solution :(i) Effective resistance of TWO `8Omega` resistors`(1)/(R)=(1)/(8) +(1)/(8)=(2)/(8)` `R=4 Omega` (ii) Current flowing through the CIRCUIT = current flowing though `4Omega` Equivalent resistance of the circuit =` 4 Omega+ 4 Omega` `= 8 Omega` Current flowing in the circuit `= (V)/(R) = (8V)/(8 Omega)= 1 A ` (iii) Potential difference across `4Omega = V_(1) = IR_(1)` `= 1A xx4 Omega= 4V ` (iv) POWER dissipated in `4 Omega= P = VI = 4 V xx1 A ` = 4 watt (v) Both `A_(1)` and `A_(2)` show same reading because current remains same in series combination. |
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| 8976. |
Which of the following statements correctly defines a volt? (a) a volt is a joule per ampere. (b) a volt is a joule per coulomb. |
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Answer» |
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| 8977. |
Sanjay was going to his office in his car. While driving his car, Sanjay saw a man behind him on a motorcycle through his rear-view mirror. A woman was also sitting behind the man on the motorcycle. Through his rear-view mirror, Sanjay noticed that the saree of the woman was almost touching the spokes of motorcycle wheel. He signalled the motorcyclist to stop and alerted the woman. She tied her saree properly and thanked Sanjay for the alert. (a) What kind of mirror is used by Sanjay as rear-view mirror ? (b) State two characteristics of the image formed by such a rear-view mirror ? (c) What could have happened if Sanjay had not alerted the woman sitting at the back of motorcycle ? (d) What values are displayed by Sanjay in this incident ? |
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Answer» Solution :(a) Convex mirror. (b)The characteristics of the image FORMED by rear-view mirror (which is a convex mirror), are (i) virtual and erect, and (ii) diminished (smaller than the object). (c) If Sanjay had not alerted the woman sitting at the back of motorcycle, then her saree could get entangled in the spokes of moving motorcycle wheel and cause a SERIOUS accident. (d) The VALUES displayed by Sanjay in this incident are (i) Vigilant (because he kept CAREFUL watch for possible danger around him) (ii) Concern about others (here he was CONCERNED about the safety of the woman), and (iii) Responsible citizen (because he stopped the motorcycle and alerted the woman about impending danger to her life). |
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| 8978. |
Why do we prefer a convexx mirror as a rear-view mirror in vehicles ? |
| Answer» SOLUTION :We prefer a CONVEX mirror as a rear-view mirror in vehicles because a convex mirror gives an erect and diminished IMAGE. As a result, convex mirror HELPS the DRIVER to have a much wider field of view. | |
| 8979. |
Why does a copper vessel devlop with green coating in rainy season ? |
| Answer» SOLUTION :Oxygen, CARBON dioxide and watervapour of the air attack COPPER metal formating green COLOURED basic coper carbonate. The formula is `CuCO_(3), Cu(OH)_(2)`. | |
| 8980. |
The violation of any law of conservation indi- cates that |
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Answer» the event will surely take place |
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| 8981. |
On what basis and how are the orbits of artificial satellites classified ? |
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Answer» Solution :ORBITS of artigical satellite can be classified on the basis of (1) the angle of the orbital plane: Orbital plane of a satellite can be at angle to it the nature of the orbit : Oibit : Orbital plane can be CIRCULAR or ELLIPTICAL in shape the height of the stallite : from the earth' surface  A satellite orbiting at a height equal to or GRATER than 35780 km above the earth's suface is called a MEDIUM Earth Oribit satelliete. Orbits of stalletes A satellite orbiting at a height between 180 km above the earth's surface is called a Low Earth Oribit stallite . |
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| 8982. |
If one moves from the surface of the earth to the moon, what will be the effect on its weight |
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Answer» WEIGHT of the PERSON decreases continuously with height from the SURFACE of the earth. |
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| 8983. |
Eenergy obtained from fossil fuels is not green energy. Is this statement true? Justify. |
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Answer» Solution :Fossil fuels like petrol, diesel or natural gas when burnt, emit TOXIC gases and SOOT particles. Thus, fossil fuels CAUSE air pollution. Burning of fossil fuels cause increased levels of carbon dioxide, carbon monoxide and nitrogen dioxide. The increased carbon dioxide EMISSION results in global warming. Nitrogen oxide results later in acid-rain.Soot particles generated through burning of fuels cause respiratory problems like asthma. Moreover, the fossil fuels are non-renewable and exhaustible fuels. They have to be explored from the deeper layers of the earth causing lots of environmental problems. Green energy is sustainable, renewable and abundant. It never creates any environmental problems and non-polluting. Thus, energy OBTAINED from fossil fuels is not at all a green energy. |
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| 8984. |
Devansh was asked to identify the test tube containing acetic acid out of the four test tubes A,B,C and D filled with different liquids. He smelled each of them and found. (i) A gave very sweet smell. (ii) B gave lighly pungent smell. (iii) C was odourless. (iv) D gave a bad odour. Which test tube contains acetic acid? |
| Answer» Solution :Test TUBE B contains acetic acid because acetic acid has a lightly PUNGENT SMELL. | |
| 8985. |
We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror ? What is the nature of the image ? Is the image larger or smaller than the object ? Draw a ray diagram to show the image formation in this case. |
Answer» SOLUTION :Range of the distance of the object = 0 to 15 cm from the POLE of the mirror. Nature of the image = VIRTUAL erect and LARGER than the object.
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| 8986. |
Draw the diagram of an electric circuit in which the resistors R_(1), R_(2) and R_(3) are connected in parallel including an ammeter and a voltmeter and mark the direction of the current. |
Answer» SOLUTION :
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| 8988. |
which type of charge (Positive or negative) flows through an electric wire when it is connected in an electric circuit ? |
| Answer» SOLUTION :Negative TYPE of charge flows through an electric wire when it is CONNECTED in an electric circuit. | |
| 8989. |
What precautions should be taken to avoid the overloading of domestic electric circuits? |
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Answer» SOLUTION :(i) Too many elecrical appliances should not be OPERATED on a SINGLE socket. (ii) Too many high POWER RATING electrical appliances should not be switched on at the same time. |
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| 8990. |
Why are local need and local knowledge of forest dwellers important for maintaining forests ? |
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Answer» SOLUTION :Needs and KNOWLEDGE of the local people needs to be given DUE consideration for maintaining forests . This gives an insight on how the resources can be used in a susutainable manner. When vast area of forest land was converted to monoculturesof pine , teak , eucalyptus , etc , a large amount of biodiversity was DESTROYED and needs of local people (leaves for fodder , herbs for medicines , fruits and nuts for food) could no LONGER be met from such forests . |
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| 8991. |
How can it be proved that a magnetic field exists around a current carrying metallic wire? |
| Answer» SOLUTION :When a magnetic compass NEEDLE is placed close to the CURRENT carrying WIRE, it will GET deflected. | |
| 8992. |
Which property light is explained in the figure? Define it . |
| Answer» Solution :Dispersion of LIGHT is EXPLAINED in the figure.The PROCESS of separation of light into its component colours while passing through a MEDIUM is called the dispersion of light. | |
| 8993. |
Differentiate stokes line and antistokes lines. |
Answer» SOLUTION :
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| 8995. |
Three resistors of resistance 5 ohm, 3 ohm and 2 ohm are connected in series with 10 V battery. Calculate their effective resistance and the current flowing through the circuit. |
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Answer» Solution :`R_(1)=5OMEGA,R_(2)=3OMEGA,R_(3)=2OMEGA,V=10V` `Rs=R_(1)+R_(2)+R_(3)`, `R_(s)=5+3+2=10`, hence `R_(s)=10Omega` The current, `I=(V)/(R_(s))=(10)/(10)=1A` |
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| 8996. |
If V_B, V_G , V_Rbe the velocity of blue , green and red light respectively in a glass prism, then which of the followingstatement gives, the correct relation ? |
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Answer» `V_(B)=V_(G)=V_(R)` |
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| 8997. |
Whether the incidence shown in the following picture is rational ? Expenses you opinion ? (##NVT_SCI_TECH_DIG_X_P2_C09_E13_004_Q01.png" width="80%"> |
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Answer» Solution :In the picture is seen a women asking the BEGGAR to move away.The beggar looks dirty and sick. In one way ,the picture looks PROPER as the beggar may be causing inconvenience to the people in that HOUSE. He is unhygienic any way spread the infection. But from the humanitarian POINT of view he may be needing help. He way be straved,He may be sick In such case. he should be given food . However ,if he is a drug addict the police should be called and person should be transferred immediately From the picture the EXACT condition of the man is not clearly understood and hence, the exact opinion about the rationality of the incidence cannot be made. |
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| 8998. |
A student fixes a sheet of white paper on a drawing board. He places a bar magnet in the centre of il He sprinkles some iron fillings uniformly around the bar magnet Then he taps the board gently and observes that the iron fillings arrange themselves ina paticular pattern. (i) Why do the iron filings arrange in a pattern (ii) What does the lines along which the iron fllling align represent (iii) What does the crowding of iron filling at the end of the magnet indicate (iv) How does strength of magnetic field is indicates ? |
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Answer» Solution : (l) Due to the FORCE exerted by the magnet within its MAGNETIC field. (ii) The lines represent magnetic field lines. (iii) Crowding of IRON fillings at the ends of the magnet indicates that the magnetic field is strongest near the poles of the magnet. (IV) The strength of magnetic field is indicated by the CLOSENESS of the field lines. Closer the lines, more will be the strength and farther the lines, lesser will be the field strength. |
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| 8999. |
Determine the direction of the force on the wire in the above experiment of apply your knowledge Q.10 and verify you finding. |
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Answer» Solution :i. From the above experiment, it is determined that the DIRECTION of the force on the wire is perpendicular to both the MAGNETIC field and the direction of the CURRENT. ii. It is verified USING Fleming's left hand rule. |
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| 9000. |
1 mole of any substance contains____molecules. |
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Answer» `6.023xx10^(23)` |
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