9264 + Interview Questions in Physics in Class 10 Page 23 InterviewSolution

1101.	Why are the arabari forests of bengal knows to be good example of conversed forests ?
Answer» SOLUTION :The FOREST department developed a strategy in which the villagers were involved in the protection of the forest . In return for the LABOUR , the villagers were paid and also had some benefitin harvesting operations . They were ALLOWED to collect wood and fodder on payment ofnominal fee . In thisway , by the active and WILLING participation of the local people , the sal forests of Arabari were conserved .

Discussion

1102.	Name two homologousstructures in vertebrates. How do such organs help in understanding evolutionary relationship ?
Answer» Solution :`` Two homologous structures: (i) LIMBS of birds and reptiles (ii) Limbs of reptiles and AMPHIBIANS `` Homologous structures INDICATE common ANCESTRY.

Discussion

1103.	What is the function of Oxytocin?
Answer» SOLUTION :Oxytocin HELPS in the contraction of the SMOOTH muscles of uterus at the TIME of child birth and milk ejection from the MAMMARY gland after child birth.

Discussion

1104.	Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.
Answer» Solution :Yes, by changing CURRENT in coil A, some current will be induced in coil B. The reason is that when current in coil A is changed, the MAGNETIC field AROUND A changes, so magnetic flux LINKED with nearby coil B changes, this GIVES rise to induced current in coil B.

Discussion

1105.	Which instrument is used to measure the electric current ?
Answer» SOLUTION :(i) Ammeter is used to MEASURE the current. (II) An Ammeter is CONNECTED in series with the circuit.

Discussion

1106.	_________ old is our mother Earth.
Answer» Solution :Nearly `4.54xx 10^(9)` years (around 45 CRORE 40 LAKH years)

Discussion

1107.	beta-particle are __________ charged.
Answer» SOLUTION :NEGATIVELY

Discussion

1108.	How can we write mechanical power in a manner similar to the electrical power?
Answer» <P> SOLUTION :Mechanical power is DEFINED as mechanical ENERGY PER unit time. Mechanical Power = `"Mechanical work done "/"time " i.e. P =W/t` It is measured in J/s or Watt, same as Electrical power

Discussion

1109.	Where should an object be placed so that a real and inverted image of same size is obtained by a convex lens.
Answer» 2F 0 F `gt2F` ANSWER :C

Discussion

1110.	What is the direction of magnetic field lines outside a bar-magnet?
Answer» SOLUTION :NORTH POLE to SOUTH pole.

Discussion

1111.	Biogas is considered to be a boon to the farmers. Give reason.
Answer» SOLUTION : • It is the source of excellent MANURE, rich in nitrogen and phosphosous which can be obtained from the biogas PLANT in addition to biogas. • It PROVIDES the safe, efficient and profitable disposal method for bio waste and sewage MATERIAL.

Discussion

1112.	When a (60W,220V) bulb and a (100 W, 220 V) bulb are connected in series, then which bulb will glow brighter?
Answer» SOLUTION :The RESISTANCE of the bulb is given by `R=(V^(2))/(P)`. So, the resistance of 60 W bulb is more than the resistance of 100 W bulb. When they are connected in series, the current through both bulbs is same. Hence 60 W bulb will be more BRIGHTER because `P=I^(2)R`.

Discussion

1113.	Can visible light be scattered by atmos//molecules in earth's atmosphere ?
Answer» SOLUTION :YES, as SIZE of molecule//atom is MUCH less than wavelength of light.

Discussion

1114.	For an object thrown at 45^(@) to the horizontal, the maximum height H and horizontal range R are related as
Answer» R = 16 H R = 8 H R = 4 H R = 2 H Solution :`H=(U^(2)SIN^(2)45^(@))/(2g)=(U^(2))/(4G)`, `R=(U^(2)sin90^(@))/(G)=(U^(2))/(g)` `therefore R=4H`

Discussion

1115.	If we say that the focal length of a spherical mirror is n times its radius of curvature, then n must be
Answer» `2.0` `1.5` `0.2` NONE of these SOLUTION :`f=nR=R/2` or `n=1/2=0.5`

Discussion

1116.	How do you appreciate efforts of a must to produce melodious sound using a musical instrument by simultaneously controlling frequency and amplitude of the sounds produced by it.
Answer» Solution :1) The sounds which produce pleasing EFFECT on the ear are called musical sounds. 2) Any instrument which produces musical sound is called musical instrument. 3) The persons who plays a musical instrument to produce melodious sound is called a MUSICIAN. 4) The musician must have control on breathing concentration on the output of the sound,which is a very hard task. 5) For this the musician needs a lot of practise. 6) With the musician's practise and knowledge over musical NOTES only we can hear melodious sound OTHERWISE it could only be a noise. 7) Hence the efforts ofa musician are highly appreciable.

Discussion

1117.	Assertion : Mie scattering is responsible for the while appearance of the cloud. Reason : Mie scattering is causedby pollen, dust,smoke.
Answer» Both assertion and REASON are true and reason is correct EXPLANATION of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false Both assertion and reason are false Solution :Both assertion and reason are true and reason is correct explanation of assertion.

Discussion

1118.	A diverging lens has a focal length whose focal length is 80 cm?
Answer» SOLUTION :`-33.3` D

Discussion

1119.	Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?
Answer» Solution :RESISTANCE of the first lamp = R Resistance of second lamp = `R_(2)` `R=V^(2)/P` `R_(1)=(220xx220)/100=484Omega` `R_(2)=(220xx220)/60=2420/3Omega` They are CONNECTED in parallel `1/R=1/R_(1)=1/R_(2)=1/484+3/2420` `R=(484xx2420)/(3(484+2420/3))=605/3Omega` Therefore `I=V/R=(220xx2)/605=8/11A` I = 0.727 A.

Discussion

1120.	Ionising power of a alpha-ray is 10,000 times greater than beta- rays.
Answer» Solution :Ionising POWER pf `alpha`-RAYS is 10,000 TIMES GREATER than gamma rays.

Discussion

1121.	The resistance of an alloy:
Answer» increase with TEMPERATURE DECREASE with temperature is constant with rise in temperature is zero Solution :The RESISTANCE of an alloy increase with increase in temperature.

Discussion

1122.	Your brother studying in XII has development the stress.
Answer» SOLUTION :The syllabus for class XII is vast. If the studies are not TAKEN seriously from the befining of the academic year,then the stress develops due to the fear of EXAMINATION and result.Therefore instead of being stressed, he should pracitse time management and study schedule. He should think of only one subject at a time,The atmosphere in the HOUSE should be maintained happy and tension-free Everybody in the house should interact with him so that he gets a feeling that he is not alone. He should be CONVINCED " study is for youare not for study"

Discussion

1123.	NH_(3) + HCl to NH_(4)Cl : Combination reaction::Fe+ CuSO_(4) to FeSO_(4) + Cu : _________
Answer» SOLUTION :DISPLACEMENT REACTION

Discussion

1124.	1eV = _______ joule.
Answer» SOLUTION :`1.602xx10^(-19)`

Discussion

1125.	Define velocity of a sound wave.
Answer» Solution :The distance TRAVELLED by a SOUND wave in unit TIME is called the VELOCITY of a sound wave. `:."Velocity"=("Distance")/("Time TAKEN")`

Discussion

1126.	A certain form of energy which is not sourced directly or indirectly from the sun and does not cause any pollution is very easily converted into electricity. This form of energy is, however, not available everywhere. Moreover, it is technically very difficult and expensive to obtain it. Name the form of energy.
Answer» ANSWER :GEOTHERMAL ENERGY

Discussion

1127.	What is atmospheric refraction ? Briefly explain. Why does apparent position of a star appear different from its true position ?
Answer» Solution :Atmospheric air layer just near the earth surface is comparatively denser and upper LAYERS of atmosphere are successively rarer and more rarer. Hence, a LIGHT ray passing through atmospheric air UNDERGOES refraction. Since the physical conditions of air are not stationary, the apparent position of the DISTANT object, as seen through the air, fluctuates. It is known as an effect of atmospheric refraction. Light coming from a distant star on entering into the earth.s atmosphere gradually bends towards the normal on account of atmospheric refraction. Hence, the star appears slightly higher actual position when VIEWED near the horizon.

Discussion

1128.	Give the law of combination of resistances in series.
Answer» Solution :Combination of resistors in series : `R_(eq)=R_(1)+R_(2)` i.e., the EFFECTIVE resistance is equal to the sum of the individual RESISTANCES

Discussion

1129.	Hot object : Heat lost : : ____ : Heat gained
Answer» ANSWER :COLD OBJECT

Discussion

1130.	A stick immersed in water appears bent because of ………….. Of light.
Answer» REFLECTION refraction scattering dispersion Answer :A::C

Discussion

1131.	Voltmeter , Ammeter, Galvanometer, Thermometer.
Answer» Solution :THERMOMETER. It MEASURES temperature, the REMAINING three MEASURE electrical QUANTITIES.

Discussion

1132.	The equivalent resistance of a series combination of two resistors is '9 Omega' and the equivalent resistance of a parallel combination of the same two resistors is 2 Omega. Find the resistances of the resistors.
Answer» Solution : Suppose two unknown resistances are x and y. When the resistors are connected in parallel `(xy)/(x +y) = 2Omega` andwhen they are connected in series `x +y = 9 Omega` So, `(xy)/9 = 2 :.Xy = 18 Omega` Now, From`x +y = 9 , y = 9-x` `:. x (9-x) =18` `:. 9 x -x^2 =18` `:. x^2 -9x + 18 = 0` `:. x- 6X - 3x + 18 =0` `:. x(x-6)-3 (x-6)=0` `:.(x -3) (x -6) =0` `:. x =3 Omega or x = 6Omega` Hence `y = 9-x =9-3 = 6 Omega or y =9 -6 = 3OMEGA` THUS, ` x=3 Omega and y = 6Omega or x =6 Omega and y = 3Omega`

Discussion

1133.	Area under v-t graph represents a physical quantity which has the unit
Answer» `m^(2)` `m` `m^(3)` `ms^(-1)` ANSWER :B

Discussion

1134.	Mention the phenomena responsible for the following. Tyndaleffect.
Answer» ANSWER :SCATTERING

Discussion

1135.	Mention the Medicinal value of Leech.
Answer» Solution :(i) They can be used to TREAT cardiovascular DISEASES. (II) Biochemical substances derived from leech saliva are used for preparation of PHARMACEUTICAL drugs that can treat hypertension.

Discussion

1136.	Assertion (A) : The poles of a magnet cannot be separated by breaking into two parts. Reason (R) : In nature magnetic monopoles do not exist.
Answer» Both (A) and (R) are true and (R) is CORRECT EXPLANATION of the assertion Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :In magnetism we ALWAYS have MAGNETIC dipolesonly. Individual (single ) magnetic poles are not possible .

Discussion

1137.	Define electric potential and potential difference.
Answer» Solution :Electric Potential : The electric potential at a POINT defined as the amount of work done in MOVING a unit positive charge from INFINITY to that point against the electric force. Electric Potential Difference : The electric potential difference between TWO points is defined as the amount of work done in moving a unit positive charge from one point to another point against the electric force .

Discussion

1138.	What is non-conductor ?
Answer» Solution :The MATERIAL which cannot transfer charge FROME ONE place to ANOTHER place is called a non-conductor.

Discussion

1139.	What factors increase the speed of d.c. motor ?
Answer»

Discussion

1140.	One Rutherford (Rd) is equal to ....... disintegrations per second.
Answer» SOLUTION :`10^(6)`

Discussion

1141.	If a substance is heated or cooled, the linear expansion occurs along the axis is
Answer» X or- X Y or- Y both (a) and (b) (a) or (b) Solution :When substance is heated its EXPANSION is positive i.e., can be taken along EITHER +X or + Y direction. But when substance is cooled its either length, or area or VOLUME decreases i.e. with respect expansion it is OPPOSITE direction i.e. either-X or -Y direction respectively,

Discussion

1142.	An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmetu, four cells. of 1.5V each and a plug key wu Id up. Draw a diagram of this drcuit in the 'ON' po1ltlon. Following graph Wi8 plotted between the value of potential difference (V) and electric current (I). State the concluion that you draw about the relation between V and I from thll graph.
Answer» Solution :Placement of ammeter, voltmeter, direction of current 4 cells in series with a closed key. RELATION : For a GIVEN resistance, current flowing through a conductor is directly proportional to potential DIFFERENCE across it, if other physical conditions REMAIN constant i.e., `V propI` .

Discussion

1143.	A student performs an experiment to estimate the focal length of a convex lens by obtaining the image of a distant window on a white screen. The image formed on the white screen is :
Answer» VIRTUAL, ERECT and magnified real, erect and magnified real, INVERTED and diminished virtual, inverted and diminished Solution :NA

Discussion

1144.	Give examples of different movements running by Government for making social life healthy.
Answer» Solution :1. Unified Movement against Tobacco- This mivement has been started by 45 different well-known organizations like WHO, Tata trust. Etc. This movement is active for controlling the tobacco consumption and providing guidnce to activists against TABACCO. 2. SALAAM MUMBAI Foundation - This organization runs programs in various schools in mumbai to empower the children living in slum area in the field of education, sports, arts and business. This organization encourages the children to take education by helping them to improve their health and lifestyle. 3. Helplines - Phone number /helpline numbers arc published in newspaper to HELP the children in distress or facing any type of problem. Children contact the helping to narrate their problems. PROPER help and guidlines are offered to children.

Discussion

1145.	State the Periodic Law on which the Modem Periodic Table is based
Answer» SOLUTION :PROPERTIES of ELEMENTS are a periodic function of ATOMIC number

Discussion

1146.	A current flows through a horizontal power line from east to west. Whatis the direction of magnetic field at a point directly below it ?
Answer» Solution :APPLYING the right-hand thumb RULE, the direction of magnetic field to towards SOUTH at a point below the power LINE.

Discussion

1147.	A block slides down as incline of 30^@ with the horizontal. Starting from rest, it covers 8 m in the first 2 seconds. Find the coefficient of static friction
Answer» Solution :USE `s=ut+1/2 at^(2)` `a=(2S)/(t)" as u"=0` `mu=(G sin theta-a)/(g cos theta)` PUTTING the value and solving `mu=`

Discussion

1148.	Which mirror can produces a virtual,erect and diminished images of an object ?
Answer» CONVEX MIRROR CONCAVE mirror Plane mirror Both concave and convex mirror Solution :Convex mirror

Discussion

1149.	If mass of a body is M on the earth surface, then the mass of the same body on the moon surface is
Answer» `M"/"6` ZERO `M` NONE of these Answer :C

Discussion

1150.	Your friend has developed the hobby of snapping selfiesl,
Answer» SOLUTION :(i) Person indulging in selfie is not aware about the world around and the RISKS. (ii) I will advise my friend to stop this weird behaviour as preactive of taking selfies has led to many deaths. (III) I will suggest him that the habit of taking selfies many times a day is disturbing your personal, social and prefessional life. (IV) I will recommend him to develop some hobbies like reading books or playing sports tohelp him GET rid of this babit.

Discussion

Explore topic-wise InterviewSolutions in .

Why are the arabari forests of bengal knows to be good example of conversed forests ?

Name two homologousstructures in vertebrates. How do such organs help in understanding evolutionary relationship ?

What is the function of Oxytocin?

Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.

Which instrument is used to measure the electric current ?

_________ old is our mother Earth.

beta-particle are __________ charged.

How can we write mechanical power in a manner similar to the electrical power?

Where should an object be placed so that a real and inverted image of same size is obtained by a convex lens.

What is the direction of magnetic field lines outside a bar-magnet?

Biogas is considered to be a boon to the farmers. Give reason.

When a (60W,220V) bulb and a (100 W, 220 V) bulb are connected in series, then which bulb will glow brighter?

Can visible light be scattered by atmos//molecules in earth's atmosphere ?

For an object thrown at 45^(@) to the horizontal, the maximum height H and horizontal range R are related as

If we say that the focal length of a spherical mirror is n times its radius of curvature, then n must be

How do you appreciate efforts of a must to produce melodious sound using a musical instrument by simultaneously controlling frequency and amplitude of the sounds produced by it.

Assertion : Mie scattering is responsible for the while appearance of the cloud. Reason : Mie scattering is causedby pollen, dust,smoke.

A diverging lens has a focal length whose focal length is 80 cm?

Two lamps, one rated 100 W at 220 V, and the other 60 W at 220 V, are connected in parallel to electric mains supply. What current is drawn from the line if the supply voltage is 220 V?

Ionising power of a alpha-ray is 10,000 times greater than beta- rays.

The resistance of an alloy:

Your brother studying in XII has development the stress.

NH_(3) + HCl to NH_(4)Cl : Combination reaction::Fe+ CuSO_(4) to FeSO_(4) + Cu : _________

1eV = _______ joule.

Define velocity of a sound wave.

What is atmospheric refraction ? Briefly explain. Why does apparent position of a star appear different from its true position ?

Give the law of combination of resistances in series.

Hot object : Heat lost : : ____ : Heat gained

A stick immersed in water appears bent because of ………….. Of light.

Voltmeter , Ammeter, Galvanometer, Thermometer.

The equivalent resistance of a series combination of two resistors is '9 Omega' and the equivalent resistance of a parallel combination of the same two resistors is 2 Omega. Find the resistances of the resistors.

Area under v-t graph represents a physical quantity which has the unit

Mention the phenomena responsible for the following. Tyndaleffect.

Mention the Medicinal value of Leech.

Assertion (A) : The poles of a magnet cannot be separated by breaking into two parts. Reason (R) : In nature magnetic monopoles do not exist.

Define electric potential and potential difference.

What is non-conductor ?

What factors increase the speed of d.c. motor ?

One Rutherford (Rd) is equal to ....... disintegrations per second.

If a substance is heated or cooled, the linear expansion occurs along the axis is

A student performs an experiment to estimate the focal length of a convex lens by obtaining the image of a distant window on a white screen. The image formed on the white screen is :

Give examples of different movements running by Government for making social life healthy.

State the Periodic Law on which the Modem Periodic Table is based

A current flows through a horizontal power line from east to west. Whatis the direction of magnetic field at a point directly below it ?

A block slides down as incline of 30^@ with the horizontal. Starting from rest, it covers 8 m in the first 2 seconds. Find the coefficient of static friction

Which mirror can produces a virtual,erect and diminished images of an object ?

If mass of a body is M on the earth surface, then the mass of the same body on the moon surface is

Your friend has developed the hobby of snapping selfiesl,