Explore topic-wise InterviewSolutions in .

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.

6451.

Complete the following table :(b) How is ozone formed at the higher levels of atmosphere ?

Answer»

Solution :
(b) Ozone at the higher levels of the atmosphere is a PRODUCT of UV RADIATION acting on oxygen `(O_2)` molecule. The higher energy UV RADIATIONS split apart some moleculer oxygen `(O_2)` into free oxygen (O) atoms. These atoms then COMBINE with the MOLECULAR oxygen to form ozone as shown :
`O_2overset(UV)rarrO" + "O`
`O" + "O_2rarrunderset(("Ozone"))(O_3)`
Discussion
6452.

Two identical resistors, each of resistance are connected in (i) series, and (ii)parallel, in turn to a battery of 6 V. Calculate the ratio of the power consumed in the combination of resistors in each case.

Answer»

Solution :Here `R_(1) = R_(2) = 15 Omega` and V = 6 V
(i) When the two resistors are CONNECTED in series, the EQUIVALENT resistance `R_(S)` of the CIRCUIT is.
`R_(S) = R_(1) + R_(2) = 15 + 15 = 30 Omega`.
`:.` Power consumed in series combination of resistors, `P_(S) = (V^(2))/(R_(S)) = (6 xx 6)/(30) = 1.2 W`
When the two resistors are connected in parallel, the equivalent resistance `R_(P)` of the circuit is,
`(1)/(R_(P)) = (1)/(R_(1)) +(1)/(R_(2)) = (1)/(15) + (1)/(15) =(2)/(15) rArr R_(P) = (15)/(2) = 7.5 Omega`
`:.` Power consumed in parallel combination of resistors,
`rArr P_(P) = (V^(2))/(R_(P)) = (6 xx 6)/(7.5) = 4.8 W rArr (P_(S))/(P_(P)) = (1.2W)/(4.8W) = (1)/(4)`
Discussion
6453.

Write the full name of the technique used in locating (a) position of an aeroplane in space, (b) position of an object under water.

Answer»

SOLUTION :RADAR `→` RADIO DETECTION and RANGING.
Discussion
6454.

Rate of breathing in aquatic organisms is much faster than that in terrestrial organisms. Give reasons

Answer»

Solution :The rate of breathing is slower in terrestrial ORGANISMS as compared to aquatic organisms. This is due to the FACT that in water, the amount of `O_(2)` is LESS as compared to air while in aquatic animals the rate of breathing is faster.
Discussion
6455.

Why does a bulb glow immediately when we switch on ?

Answer»

Solution :When we switch on any electric circuit, irrespective of length of the CONDUCTOR, an electric field is set up THROUGHOUT the conductor instantneously due to VOLTAGE of the source connected to the circuit. This electric field makes all electrons to move in a specified DIRECTION simultanceouly. hence the bulb GLOWS.
Discussion
6456.

(a) Difine (i) principal focus of a convace mirror, and (ii) focal length of a concave mirror. (b) Draw diagram to represent the action of a concave mirror on a beam of parallel light rays. Mark on this diagram principal axis, focus F, centre of curvature C, pole P and focal lenght f, of the concave mirror.

Answer»
Discussion
6457.

Show that the motion of a simple pendulum is simple harmonic derivean eqaution for its time period. What is a seconds pendulum?

Answer»

Solution :Simple PENDULUM: Massive metallic bob is susupended from a rigid support with the help of inextensablethread. This arrangement is KNOWN as simple pendulum.

So length of simple pendulum is 'l. Let the pendulum is pulled to a side by a small angle `'theta'` and released it oscillate about the mean POSITION.
Let the bob is at once extreme position B. The weight `(W=mg)` of body acts vertically downwards.
By resolving the weight into two perpendicular components:
1) One component mg `sintheta` is responsible for the to and fro motion of pendulum.
2) Other components mg `costheta` will balance the TENSION in the string.
Force useful for motion `F=mgsintheta =ma`(From Newton's 2nd Law)
From the above equations
`therefore a=g sin theta`
when `theta` is small `sin theta ~~theta=(arc)/(radius)=(x)/(l)`
`therefore a=g(x)/(x).............(1) rArr a prop x`
Since acceleration is proportional to displacement and acceleration is always distracted towards a fixed point the motion of simple pendulum is "simple harmonic".
Time period of simple pendulum:
Time period of pendulum `= 2PI sqrt(Y/a) =2pisqrt(("displacement")/("acceleration"))`
From equation(1) `a=(g)/(l)xxor (x)/(a)=("displacement"(y))/("acceleration"(a))=(l)/(g)`
`therefore` Time period of simple pendulum. `T=2pisqrt(l/g)`
Seconds pendulum: A pendulum whose time period is 2 seconds is called "seconds pendulum".
Discussion
6458.

Name the two devices that work using heat energy of the sun.

Answer»

SOLUTION :SOLAR COOKER and solar CELL
Discussion
6459.

Suggest two ways to conserve forests?

Answer»

SOLUTION :• By PLANTING more TREES. • By BANNING CUTTING of trees.
Discussion
6460.

Which one of the following materials cannot be used ot make a lens?

Answer»

water
glass
plastic
clay

Answer :D
Discussion
6461.

Bharat had an electric iron . He connected it into two - pin plug . Obviouslythe green wire was left unconnected . Afte few day , once his sistergot a severe electric shockwhile ironing the clothes . Bharatcalled the electriction. He toldthat this situation could have been avoided if she would have connceted the green wirealsoby usinga three - pin plug . Bharat learnt a lesson .Whichterminal gets connected by usinga green wire ?

Answer»

Solution :Earthing TERMINAL gets connected USING a green WIRE .
Discussion
6462.

The value of Avogardo number____________.

Answer»

SOLUTION :`6.023xx10^(23) //MOL (or) mol^(-1)`
Discussion
6463.

A small aluminium rod AB is suspended horizontally from a stand by the ends of two connecting wires as shown in the Figure given here. A horseshoe magnet is placed in such a way that north pole of the magnet is vertically below and its south pole vertically above the aluminium rod. The aluminium rod is connected in series with a battery, a key and a rheostat. How do you think the displacement of rod AB will be affected if : (i) current in rod AB is increased ? (ii) a stronger horseshoe magnet is used ? (iii) length of the rod AB is increased ?

Answer»

Solution :In order to answer this question, we have to remember that : When a CURRENT-carrying conductor is perpendicular to the magnetic field, the force acting on it is directly proportional to (a) magnetic of current flowing in the conductor (b) strength of magnetic field applied, and (c) length of the conductor. And greater the force, greater will be the displacement of the conductor (which is an aluminium rod in this CASE). Now :
(i) if the current in rod AB is increased, then more force will act on the rod and hence the displacement of rod will also be more.
(ii) if a stronger horseshoe MAGNET is USED, then the strength of magnetic field will increase leading to greater force on the rod. And DUE to greater force, the displacement of rod will also be more.
(iii) If the length of rod AB is increased, then more force will act on the rod and hence the displacement of rod will also be more.
Discussion
6464.

Bharat had an electric iron . He connected it into two - pin plug . Obviouslythe green wire was left unconnected . Afte few day , once his sistergot a severe electric shockwhile ironing the clothes . Bharatcalled the electriction. He toldthat this situation could have been avoided if she would have connceted the green wirealsoby usinga three - pin plug . Bharat learnt a lesson .If you were the electrictian , whatelsewouldyou doapart form mere explainingto Bharat?

Answer»

SOLUTION :As an ELECTRICIAN , I would CHECK all other device at his houseregardingproper earthing . I wouldalsocheck overloading, if any in thehouse-hold CIRCUITS.
Discussion
6465.

Bharat had an electric iron . He connected it into two - pin plug . Obviouslythe green wire was left unconnected . Afte few day , once his sistergot a severe electric shockwhile ironing the clothes . Bharatcalled the electriction. He toldthat this situation could have been avoided if she would have connceted the green wirealsoby usinga three - pin plug . Bharat learnt a lesson .Whatcare should Bharat take to avoid such mistakes ?

Answer»

Solution :Bharat should be more CAREFUL in futureregarding safety measure and PUT theminto partice.
Discussion
6466.

State two important advantages of alternating current over direct current.

Answer»

Solution :(a) Alternating current reverses its direction periodically but direct current always flow in ONE direction.
(b) AC electric power can be TRANSMITTED over long DISTANCES WITHOUT much less of energy while DC can not.
Discussion
6467.

How do the eyes of a tiger difer from that of a rabbit ?

Answer»

SOLUTION :Eyes of a tiger are in FRONT of the head. So it has a LESSER field of view but a wider binocular-vision field which helps it to GAUGE DISTANCE of the objectsclearly. Eyes of a rabbit are on the opposite sides of its head, so it has a wider field of view but a lesser binocular -vision field.
Discussion
6468.

Calculate the number of electrons constituting one coulomb of charge.

Answer»

Solution :We KNOW that the electron have charge of `1.6xx10^(-19)C`. Then `6.65xx10^(18)` electrons constitute a coulomb of charge, E = `1.6xx10^(-19)C`. Total charge required I Coulomb, the NUMBER of electrons CONSTITUTING one coulomb of charge.
Discussion
6469.

Distinguish between Non-Chordates and Chordates :

Answer»

SOLUTION :
Discussion
6470.

In the recoilingof a gun on firing , both the linearmomentum and kinetic energy are conserved .

Answer»


Solution :CORRECTSTATEMENT : Only LINEAR momentum is conserved kinetic ENERGY INCREASE .
Discussion
6471.

Yoga is limited for asaans and pranayam only.

Answer»

Solution :False.
Yoga is not LIMITED for ASANAS and pranayam, but includes discipline, BALANCED and good food, and meditation also.
Discussion
6472.

In the following circuit A, B and C are three ammeters. 0.5A current is shown by ammeter B. Find the total resistance of the circuit.

Answer»

SOLUTION :`4 OMEGA`
Discussion
6473.

The calorific values of three fuels A, B and C are 33 kJ/g, 48 kJ/g and 150 kJ/g, respectively. A is solid, B is liquid and C is a gas at room temperature. On combusion, both A and B produce carbon dioxide while C explodes forming steam. B and C leave no residue after combustion while A leaves behind some solid residue. Which one of the three fuels si the most ideal ? Give two reasons to support your answer.

Answer»


Answer :Fuel B is the most IDEAL fuel; (i) Leaves no residue on burning (II) High calorific VALUE of 48 kJ/g(iii) Does not BURN explosively
Discussion
6474.

From the above table, Which material has high conductivity ?

Answer»

SOLUTION :COPPER has HIGH CONDUCTIVITY.
Discussion
6475.

A partition divides a container having insulated walls into two compartments I and II. The same gas fills the two compartment. What is the ratio of the number of molecules in compartments I and II ?

Answer»

Solution :`N=(PV)/(kT)`, `n'=(2p2V)/(kT)`
`n//n'=(1)/(4)`
Discussion
6476.

What determinedthe frequencyof AC produced by a generator ?

Answer»

Solution :The frequencyof AC produced by agenerator is DETERMINED by the ROTATION of the COIL and is equal to the frequencyof rotation of the coil .
Discussion
6477.

Do you see any vibrations in the tuning fork?

Answer»

Solution :YES, we can SENSE the vibrations in the TUNING fork.
Discussion
6478.

An ideal gas undergoes isothermal process from some initial state i to final state f. Choose the correct alternatives.

Answer»

`DU=0`
`"d"THETA=0`
`"d"theta=dU`
`dw=dw`

SOLUTION :In isothermal PROCESS dU = 0
From `"d"theta = dU + dW ` when `dU = 0 rarr "d"theta = dW`
Discussion
6479.

Study the electric circuit of Fig. 12.30 and find (i) the current flowing in the circuit and (ii) the potential difference across 10 Omega resistor.

Answer»

Solution :(i) Here V=3V, `R_1=10 OMEGA and R_2=20 Omega` Since `R_1 and R_2` are connected in series the effective resistance of the circuit
`R=R_1+R_2=10+20=30 Omega`
`THEREFORE` Current FLOWING in the circuit `I=V/R=3/30=0.1A`
(ii) The potential difference across `R_1=10 Omega` resistor is `V_1=IR_1=0.1 times 10=1.0 V`
Discussion
6480.

The sky appears dark to passengers flying at very high altitudes mainly because:

Answer»

scattering of LIGHT is not ENOUGH at such HEIGHTS.
there is no atmosphere at great heights.
he size of molecules is smaller than the wavelength of VISIBLE light.
the light GETS scattered towards the earth.

Solution :There is no atmosphere at great heights, hence there is no scattering of light.
Discussion
6481.

Which of the two prisms, A made of crown glass and B made of flint glass, deviates a ray of light more ?

Answer»


ANSWER :B MADE of FLINT GLASS.
Discussion
6482.

Does disperson occur in a follow prism ? Given reason.

Answer»

Solution :No. Dispersion occurs when INCIDENT light is REFRACTED by the glass of the prism which is a denser medium compared to air. A hollow prism is be filled with air and hence there is no denser medium, where refraction can OCCUR. Hence, no dispersion SHALL occur. If the hollow prism is filled with a proper denser medium, dispersion becomes possible.
Discussion
6483.

Nature is the closest frined of human being.

Answer»

Solution :i. Human BEINGS are connected to nature in various ways.
ii. Hobbies such as gardening, bird watching, walking in forest, lingering n nature, rearing domestic animals, ETC. help to creacte posivite mindset and IMPROVE confidence and thus, it helps to maintain social HEALTH.
iii. Spending TIME in open environment also helps in reducing stress.
Hence, we can say that nature is the closest friend of human being.
Discussion
6484.

Calculate the resistance of a conductor through which a current of 2A passes, when the potential difference between its ends is 30V.

Answer»

Solution :Current through the conductor I = 2A
POTENTIAL Difference V = 30 V
From Ohm.s Law R-V/I
Therefore, `R=30//2=15Omega`
Discussion
6485.

Explain Raman Scattering .

Answer»

Solution :(i) When a parallel beam of monochromatic (single coloured) light passes through a gas or liquid or transparent solid, a pat of light rays are scattered.
(ii) Raman Scattering is defined as "The interaction of light ray with the particles of PURE liquids or transparent solids, which leads to a change in wavelength or frequency".
(iii) The scattered light CONTAINS some additional frequencies (or wavelengths) other than that of INCIDENT frequency (or wavelength) . This is known as Raman scattering or Raman effect.
(iv) The spectrual LINES having frequency equal to the incident ray frequency is callled 'Rayleigh LINE' and teh spectral lines which are having frequency other than the incident ray frequency are called 'Raman lines'
(v) The lines having frequencies lower than teh incident frequency is called stokes lines and the lines having frequencies higher than the incident frequency are called Antistokes lines.
Discussion
6486.

Weight of an object changes from place to plate on the surface of the Earth.

Answer»

SOLUTION :i. The shape of the Earth is not exactly spherical. It is flattened at poles, while bulged at EQUATOR.
II. Weight is the Earth's gravitational force acting on the object, which is generally `W=mg`.
III. Mass of the object remains the same but value of g keeps on changing from place to place.
iv. The value of g is maximum at poles is `9.83m//s^(2)` while it is the least at EQUATO i.e. `9.78m//s^(2)`.
v. Due to this the weight of an object changes from place to place on the surface of the Earth.
vi. It is maximum at poles but gets reduced at equator.
Discussion
6487.

l cal heat and 1 kcal heat

Answer»

SOLUTION :
Discussion
6488.

What is the direction of magnetic field lines inside a bar magnet and outside of it .

Answer»

Solution :The DIRECTION of the magnetic fieldlines is from NORTH pole to south pole OUTSIDE the magnet and from south pole to north pole inside the magnet.
Discussion
6489.

What is the role of anomalous behaviour of water in preserving aquatic life in regions of cold climate?

Answer»

Solution :1.The EXISTENCE of fish and other AQUATIC life is possible due to anomalous EXPANSION of water.
2. In regions of cold climate, the atmospheric temperature falls below `0^@C`.
3. As the atmospheric temperature falls, the water at the surface of ponds and lakes starts contracting. Its volume decreases and density INCREASES.
4. The water with higher density moves downward and thewater with lower density moves upward. This continues till the temperature of water becomes `4^@C`.
5. When the temperature of water starts decreasing below `4^@C`, water starts expanding instead of contracting. Its volume increases, density decreases and it remains at thesurface.
6. Soon, the surface water gets converted into sheet of ice. This sheet of ice acts as an insulator and does not allow the transfer of heat from water to the atmosphere.
7. Therefore, the water below the sheet of ice remains at `4^@C`.
8. Hence, due to the anomalous expansion of water, aquatic life (plants and animals)is preserved in regions of cold climate.
Discussion
6490.

A satellite of small mass burns during its descent and not during ascent. Why ?

Answer»

SOLUTION :The speed of SATELLITE during DESCENT is much LARGER than during ascent, and so heat produced is large.
Discussion
6491.

In an electric field. electric potential at point A is 40 V and that at point B is 90 V. The work to be done in taking 2 C charge from point A to point B is …………….. .

Answer»

25 J
25 J
90 J
100 J

Solution :`V_B -V_A = W/Q`
`:. W = Q(V_B - V_A)`
`=(2) (90 -40) =100J`
Discussion
6492.

When the gases sulphurdioxide and hydrogensulphide mix in the presence of water, the reaction SO_2 + 2H_2S to 2H_2O + 3Soccur. Here hydrogen sulphide is acting as

Answer»

an OXIDISING AGENT
a REDUCING agent
a DEHYDRATING agent
a catalyst

Solution :a reducing agent
Discussion
6493.

List any three parameters, which categorizes any source of energy as a good source of energy.

Answer»

Solution :(i) Does large amount of work PER unit VOLUME or mass.
(ii) EASY to store and transport.
(iii) It should be economical and easily ACCESSIBLE.
Discussion
6494.

Which metal filament is used in electric bulb ?

Answer»

Solution :Tungsten filament is USED in electric BULB since melting point of tungsten is very HIGH. Also resistivity of tungsten is high.
Discussion
6495.

At the timeof shortcircuit,the electriccurrent ……… .

Answer»

suddenlydecreases
suddenlyincreases
INSTANTANEOUSLY BECOMES ZERO
does not CHANGE

SOLUTION :suddenlyincreases
Discussion
6496.

The change in magnetic field lines in a coil is the cause of induced electric current in it. Name the underlying phenomenon.

Answer»

SOLUTION :ELECTROMAGNETIC INDUCTION PHENOMENON.
Discussion
6497.

A. . . . .. . . . . .Is the display device used to give an output in the form of . . . . . . . . . .

Answer»


Answer :Seven Segment DISPLAY, NUMBERS or text
Discussion
6498.

_______ isusedtomeasureelectricresistancein acircuit

Answer»

VOLTMETER
Galvanometer
Ammeter
OHM METER

ANSWER :D
Discussion
6499.

Complete the flow chart.

Answer»

SOLUTION :
Discussion
6500.

What will you do if you have to use free space around your home for good purpose ? Why ?

Answer»

Solution :I will use the free space around my HOME in the following manner:
i. I will grow small plants and SHRUBS, which will BEAUTIFY the surroundings and also help in reducing the carbon DIOXIDE levels.
ii. I can also make the space available for PARKING of public vehicles or starting a small playground, libary, etc.
Discussion