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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.
| 3651. |
White light splits into its constituent colours when passed through a glass prism. Name the process of splitting. |
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| 3652. |
How much heat energy is necessary to raise the temperature of 5 kg of water from 20^@C to 100^@C. |
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Answer» Solution :Given : m=5 kg, c=1 KCAL/`kg^@C` Change in temperature `(DeltaT)`=100-20 =`80^@C` To Find : Heat energy needed to raise the temperature Solution :Energy to be SUPPLIED to WATER = energy gained by water = mass of water X specific heat of water change in temperature of water = `mxxcxxDeltaT` = 5 x 1 x 80 = 400 kcal HENCE, the heat energy necessary to raise the temperature of water is 400 kcal. |
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| 3653. |
Name two devices whose working is based on the heating effect of electric current. |
| Answer» SOLUTION :An ELECTRIC IRON, electric TOASTER | |
| 3654. |
What is meant by saying that the potential difference between two points is 1 V? . |
| Answer» Solution :Potential difference of 1 volt MEANS the amount of work done when a unit CHARGE MOVES from one point to the other point in an electric field. | |
| 3655. |
Three resistors of 10 Omega, 15 Omegaand 20 Omega are connected in series in a circuit. If the potential drop across the 15 Omega resistor is 3 V, find the current in the circuit and potential drop across the 10 Omega resistor. |
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Answer» SOLUTION :In series circuit same current FLOWS through all the resistors. Current through 15 `Omega` resistor `I = (V)/(R) = (3V)/(15) = (1)/(5)` =0.2 A `:.` Current in the circuit `=0.2` A `:.` Potential drop across 10`Omega` resistor is `I =(V)/(R)` `V= IR` `=0.2A xx10 Omega` =2 V |
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| 3656. |
If tow bodies are said to be in thermal equilibrium , then they will be at the _________. |
| Answer» SOLUTION :same TEMPERATURE | |
| 3657. |
Farid was given two thin wires X and Y in the science laboratory. The teacher asked Farid to find out (by performing suitable activities) which wire was 'fuse wire' and which one a 'nichrome wire'. Farid was given batteries of 3 V and 12 V, and some copper connecting wires alongwith crocodile clips. The teacher had himself performed this activity earlier and knew that the batteries of 3 V and 12 V were appropriate for this activityc. The teacher also advised Farid ot put off fan while performing the activites and take necessary precautions to avoid burns. Farid performed the activities and concluded that wire X is nichrome wire whereas wire Y is the fuse wire. (a) Describe briefly the activity which Farid could have performed to conclude that wire X is nichrome wire. (b) Describe briefly the activity which Farid could have performed to conclude that wire Y is fuse wire. (c) Why did teacher advise Farid to switch off the fan during these activities ? (d) What values are shown by Farid in performing these activities ? |
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Answer» SOLUTION :(a) Farid first connected the wire X in series circuit with 3 V BATTERY. He found that the wire got heated and became dull red. Farid then connected wire X in series circuit with 12 V battery. He found that wire X got heated too much and started glowing bright red. This showed that wire X is like the heating element of an electric heater and hence made of nichrome. (b) Farid now connected the wire Y in series circuit with 3 battery. The wire got heated a little but did not glow. Farid then connected wire Y in series circuit with 12 V battery. He found that wire Y got heated too much, melted and broke into two pieces. Now, when a thin wire gets heated too much and breaks on passing excessive electric current, it BEHAVES like a fuse wire. So, wire Y is the fuse wire. (c) The teacher advised Farid to switch off the fan while performing these activities because the fan's air could cool the hot wires due to which the fuse wire will not get heated to its melting point and hence not break. (d) The values shown by Farid in performing these activities are (i) Knowledge of the heating effect of electric current and working of fuse, and (II) Ability to apply knowledge in real life situations. |
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| 3658. |
Is water convervation necessary ? Given reasons . |
| Answer» SOLUTION :The total AMOUNT of fresh water is more than enough to MEET the needs of human beings . But its uneven distribution , wide SEASONAL as well as YEARLY fluctuation in rainfalls and water shortage are chronic problems in most parts of the world. | |
| 3659. |
Forceof action and reaction never cancel each otheras they are actingat differentbodies. |
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| 3660. |
The formulae of four organic compounds are given below :{:("A","B","C"," D"),(C_(2)H_(4),CH_(4)COOH,C_(2)H_(5)OH,C_(2)H_(6)):}(i) Which one of these compounds A, B, C or D is a saturated hydrocarbon ? (ii) Identify the organic acid and give its structural formula.(iii) Which of the above compounds when heated at 443 K in the presence of concentrated H_(2)SO_(4) forms ethene as the major product ? What is the role played by concentrated H_(2)SO_(4) in this reaction ? Also write the chemical equation involved.(iv) Given a chemical equation when B and C react with other in presence of concentrated H_(2)SO_(4). Name the major product formed and mention one of its important use. |
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Answer» Solution :(i) `D(C_(2)H_(6))` is a saturated hydrocarbon because it conforms to the formula `C_(x)H_(2x+2)`. (ii)The ORGANIC acid is `B(CH_(3)COOH)`. Its structural is `H-overset("H")overset("|")underset("H")underset("|")(C )-overset("O")overset("||")(C )-O-H` (iii)The compound `C(C_(2)H_(5)O_(4))` when heated at 443 K in the presence of conc. `H_(2)SO_(4)` forms ethene as the major product. Sulphuric acid plays the ROLE of dehydrating agent. Reaction :`C_(2)H_(5)OH overset("Conc. " H_(2)SO_(4))rarr underset("Ethene")(C_(2)H_(4))+H_(2)O` (iv)`CH_(3)COOH+C_(2)H_(5)OH overset("Conc. "H_(2)SO_(4))rarrunderset(("Ester"))underset("Ethyl ethanoate")(CH_(3)COOC_(2)H_(5))+H_(2)O` The ester is used in MAKING perfumes and flavouring agents. |
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| 3661. |
When two 2Omega resistors are connected in series, the effective resistance is. . . . . . . .. . |
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Answer» `1OMEGA` |
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| 3662. |
How much solar energy will be received by 1 m^(2) area in one hour if the solar constant be 1.4 kW//m^(2) ? |
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| 3663. |
Who was the first person to travel to moon? |
| Answer» SOLUTION :The first person to STEP on the Moon was Neil ARMSTRONG of USA | |
| 3664. |
A torch bulb is rated 5V and 500mA. Calculate (i) its power, (ii) its resistance and (iii) the energy consumed if the bulb is lighted for 4 hours. |
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Answer» SOLUTION :Here rating of TORCH bulb is V=5V and I=500mA =0.5A (i) `therefore` POWER of torch bulb `P=VI= 5 times 0.5=2.5 W` (ii) `therefore` RESISTANCE of torch bulb `R=V/l=5/0.5=10 Omega` (iii) Energy consumed by the bulb in 4 hours. `E=Pt =2.5 times 4=10 W H` |
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| 3665. |
If a number of bulbs of different wattages are joined in parallel With a voltage source, which bulb will glow With maximum brightness? |
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Answer» <P> SOLUTION :The bulb With HIGHEST wattage (here, lowest resistance) will GLOW with maximumbrightnesss as `P= V^2/R and "here " P prop 1/R`. |
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| 3666. |
A beam of light passing through a diverging lens of focal length 0.3 m appear to be focused at a distance 0.2 m behind the lens. Find the position of the object. |
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Answer» SOLUTION :f=- 0.3 m ,v =-0.2 m `(1)/(f)=(1)/(v)-(1)/(u)` `(1)/(u)=(1)/(v)-(1)/(f)` `(1)/(u)=(1)/(-0.2)-(1)/(-0.3)` `=(-10)/(6)` `u=(-6)/(10)=-0.6m` |
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| 3667. |
What are the uses of geostationary satellites? |
| Answer» SOLUTION :Geostationary SATELLITES are stationary with REFERENCE to the earth, they can OBSERVE a specific portion of the earth, continuously. Therefore, they are used in applications like meteorology and for carrying signals for telephone, television, radio etc | |
| 3668. |
Solar cells are commonly used in |
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Answer» Artificial satellites |
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| 3669. |
State the relation between colour of scattered light and size of the scattering particle.(b) The apparent position of an object, when seen through the hot air, fluctuates or wavers. State the basic cause of this observation.(c) Complete the path of white light when it passes through two identical prisms placed as shown: |
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Answer» Solution : Very fine particles scatter mainly blue light while particles of larger size scatter light of longer WAVELENGTHS. (b) Basic cause of the fluctuating or wavering position of an object seen through the hot AIR is the phenomenon of atmospheric refraction. (C) Completed PATH of light is shown here. 
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| 3670. |
State and prove the principle of conservation of angular momentum. Explain the principle of conservation of angular momentum with examples. |
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Answer» Solution : LAW of conservation of angular momentum: When no external torque is acting on a body then the angular momentum of that rotating body is constant. `I_1 omega_1 = I_2 omega_2 ( " when " tau = 0)` Explanation : Here `l_1 " and " I_2`are moment ofinertia of rotating bodies and `omega_1 " and "omega_2` are their initial and final angular velocities. If external torque `tau = 0 " then " (dvecL)/(dt) = tau = 0` `therefore` Change in angular momentum is also zero. `rArr dvecL_2 - dvecL_1 =0` i.e., ` I_2omega_2 - I_1 omega_1 = 0 " or " I_1omega_1 = I_2 omega_2` Example - 1 :A boy stands over the centres of a horizontal platform which is rotating| freely with a speed `omega_1 (n_1 " revolutions/sec ".)`about a vertical axis passing through the centre of the platform and straight up) through the boy. He holds two bricks in each of his hands CLOSE to his body. The combined moment of inertia of the system is say `I_1`. LET the boy stretches his arms to hold the masses far away from his body. In this position the moment of inertia increases to `I_2`and let `omega_2`is his angular speed. Here `omega_2 lt omega_1` , because moment of inertia increases. `because I_1omega_1 = I_2omega_2 rArr I_1 (2pi)/(T_1) = I_2(2pi)(T_2) rArr I_1 n_1 = I_2n_2` Example – 2: An athlete diving off a high| spring board can BRING his legs and hands close to the body and performs Somersault about a horizontal axis passing through his body in the air before reaching the water below it. During the fall his angular momentum remains constant. |
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| 3671. |
A team of eye specialists visited a village and examined number of villages for any vision defects. They observed that many villagers suffered from different defects of vision. They left and came back after a month with required medicines and equipment for treatment. The eye treatment camp continued for one week. The doctors as well as villagers were extremely happy after the event. Answer the following questions based on the above information: (i) Which values made the doctors happy? Name any two actions on your part as an individual which you can take to get similar kind of happiness in other everyday life situations. (ii) Assuming yourself to be a doctor in this event, suggest one more help or action related to eye defects to help the villagers further. |
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Answer» SOLUTION :(i) Empathy, service to others, concern for fellow beings. ADOPTING a needy individual or GROUP and contributing towards their free EDUCATION. Spreading awareness about health care. (Any other) (ii) Follow-up check-up, awareness about eye-care, free distribution of required SPECTACLES, etc. |
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| 3672. |
Artificial radioactivity is called natural radioactivity. |
| Answer» SOLUTION :ARTIFICIAL RADIOACTIVITY is called MAN made radioactivity. | |
| 3673. |
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass ? The speed of light in vacuum is 3 xx 10^(8) m s^(-1). |
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Answer» Solution :Given that speed of light in vacuum `c = 3 XX 10^(8) ms^(-1)`, and REFRACTIVE index of glass `n_(8) = 1.50` From the relation `n = (c)/(upsilon)`, we have Speed of light in glass `upsilon_(G) = (c)/(n_(g)) = (3 xx 10^(8) ms^(-1))/(1.50) = 2 xx 10^(8) ms^(-1)` |
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| 3674. |
Explain the occurrence of advanced sunrise and delayed sunset on the basis of atmospheric refraction. |
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Answer» Solution :i. In the morning, the Sun should be seen by the observer when it reaches the horizon, but it is seen two minutes before that. ii. As ray of LIGHT from· the Sun enters the earth's atmosphere, it follows a curved path due to refraction, before reaching the observer. III. This MAKES the apparent position of the Sun slightly higher than actual position for the observer. Hence, the Sun is seen earlier before the Sun reaches the horizon. iv. Atmospheric refraction of sunlight also occurs at the sunset. In this CASE, the observer on the earth CONTINUES to see the setting Sun for two minutes after the Sun has dipped below the horizon, thus delaying the sunset. |
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| 3675. |
Describe how a hydropower plant produces electricity. Write any two advantages of hydroelectric energy. |
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Answer» Solution :High rise dams are constructed on the river to obstruct the FLOW of water and thereby COLLECT water in large reservoirs, the water level rises and in this process the kinetic energy of FLOWING water gets transformed into POTENTIAL energy. The water from the high level in the dam is carried through pipes to the turbines, at the bottom of the dams and converted to electricity. Two advantages of hydro-energy: (i) Reservoir can be refilled everytime it rains so it is renewable SOURCE of energy. (ii) Does not cause pollution. |
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| 3676. |
(i) Identify any two parts from the above diagram which carry oxygenated and deoxygenated blood.(ii) Explain the process of double circulation with the help of a flow chart. |
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Answer» SOLUTION :(i)(a)Oxygenated blood is present in : B - Left ventricle D - Aorta F - Left auricle (b)DEOXYGENATED blood is present in : A - Right ventricle C - PULMONARY artery E - Right auricle / Vena CAVA (ii)  Since the blood enters the HEART twice [(1), (2)] to complete one cardiac cycle, hence its called double circulation. |
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| 3677. |
According to Rayleigh's law, the amount of scattering of light is inversely proportional to the fourth power of its ___________________. |
| Answer» SOLUTION :WAVELENGTH | |
| 3678. |
If instead of electron, a neutron enters a field, what will be its direction of motion ? Give reason for your answer. |
| Answer» SOLUTION :NEUTRON will CONTINUE to move in same direction because no force will act on it since it carries no CHARGE . | |
| 3679. |
If the unit of force is 100 N, unit of length is 10m and unit of time is 100 s, what is the unit of mass in this system of units ? |
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Answer» Solution :`[F]=[MLT^(-2)]` `[M]=([F])/([L][T^(-2)])=([100N])/([10m][100S]^(-2))=10^(5)KG` |
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| 3680. |
Accessory whorls : Calyx and corolla : : Essential whorls : …… |
| Answer» SOLUTION :Androceium and GYNOECIUM | |
| 3681. |
Complete the following sentences : (a) 1J= …………ealorie .(b) 1 kWh ………….J |
| Answer» SOLUTION :(a)0.24 (B) `3.6xx10^(5)` | |
| 3682. |
A student has focused the image of a candle flame on a white screen using a a concave mirror. The situation of as given below: Length of the flame =1.5 cm focal length of the mirror =12 cm Distance of flame from the mirror=18 cm If the flame is perpendicular to the principal axis of the mirror, then calculate the following: (i) Distance of the image from the mirror (ii) Length of the image If the distance between the mirror and the flame is reduced to 10 cm, then what would be observed on the screen? Draw ray diagram to justify your answer for this situation. |
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Answer» Solution :(i) `h=+1.5cm,f=-12cm,u=-18cm,v=?` `h.=?` a. `1/f=1/v+1/u` `:.1/v-1/f-1/u` `=1/((-12))-1/((-18))` `=(-1)/12+1/18=(-3+2)/36` `=(-1)/36` `v=-36cm` b. `v.=-v/uxxb` `=(-36cm)/(-18cm)xx1.5=-3cm` (Magnified inverted image) (iii) If u=-10cm No distinct image would be formed on the screen. In this CASE the image formed will be VIRTUAL (object will be within focal length) 
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| 3683. |
Autecology deals with the study of ………………. |
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Answer» FOSSILS |
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| 3684. |
Identify 'x', 'y' and 'z' in the following reaction :2KClO_3(x)overset((y))rarr2KCl(x)+O_2(z) |
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Answer» x = gas, y = REACTION CONDITION, z = gas |
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| 3685. |
Use your brain power. Why is it said that pollution control is important ? |
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Answer» Solution :i. Pollution affects the life of human beingsand other living organisms. Also, it affects other natural elements LIKE air, soil, water, etc. II. Persistence of pollutants in NATURE has adverse effects on human health and environment. iii. Anthropogenic activities like mining, etc., have negative impact on the ecosystem, biodiversity , natural resources and habitals. IV. Pollution leads to loss of biodiversity , global WARMING, reduction in number of plant and animal species, etc. v. Human health is largely impacted by degradation of environmen. Reduction in quality of air, water and other resources poses a threat of human life. Hence, pollution controlis extremely important. |
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| 3686. |
Outof the following ,which statementis wrongfor a current - carryingsolenoid ? |
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Answer» The MAGNETICFIELD insidethe solenoid is the sameat each POINT . |
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| 3687. |
2Mg + O_(2) to 2MgO |
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Answer» SOLUTION :` 2Mg + O_(2) to 2MgO` In thisreaction, OXIDATION of MG TAKES place. |
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| 3688. |
Which one of the following is not an energy source? |
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| 3689. |
Value of universal gas constant is __________________. |
| Answer» SOLUTION :`8.3 J MOL^(-1) K^(-1)` | |
| 3690. |
Complete the following for an object of mass m on On Earth's surface : A KE=1/2mv^(2) , BPE=…………… At infinity :A. KE=………….. , B. PE=0 |
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Answer» SOLUTION :On EARTH's SURFACE: a. `KE=1/2mv^(2)` , B. `PE=-(GMm)/R` At infinity : A. `KE=0`, B. `PE=0` |
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| 3691. |
A lens of focal length 5 cm is being used by a student in the laboratory as a magnifying glass. His least distance of distinct vision is 25 cm. What magnification is the student getting? |
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Answer» Solution :Given, image distance = v = -25 cm, focal length = f = 5 cm, magnification = m = ? From LENS formula, `(1)/(f) = (1)/(v) - (1)/(u) = (1)/(u) = (1)/(v) - (1)/(f)` `(1)/(u) = (1)/(-25)-(1)/(5) = (-1-5)/(25) = (-6)/(25)` Object distance `= u = (-25)/(6) cm`. We know that, `m = (v)/(u) = (-25 - 6)/(-25) = 6`. |
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| 3692. |
A small air bubble in a glass block when seen from above appears to be raised because of : |
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Answer» REFRACTION of light |
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| 3693. |
According to Ohm.s law … |
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Answer» the RESISTANCE INCREASES with an INCREASE in CURRENT. |
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| 3694. |
SI unit of resistivity is |
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Answer» `ohm//metre` |
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| 3695. |
The distance travelled by a moving body is directly proportional to time. Is any external force acting on it ? |
| Answer» Solution :As `s ALPHA t,` so acceleration a= 0, therefore, no external FORCE is ACTING on the BODY. | |
| 3696. |
Define catenation. |
| Answer» Solution :The property of self-linking of atoms of an element through bonds in ORDER to FORM straight CHAIN, BRANCHED chains or CYCLIC chains of different sizes is called catenation. | |
| 3697. |
Atthe timeof a short circult, the currentin the circuit. |
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Answer» REDUCES to zero |
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| 3698. |
Sun appears red in colour during sunrise and sunset. Give reason. |
| Answer» Solution :The light rays from the sun travel more distance in atmosphere to reacah our eye in morning and evening times. During sunrise and sunset EXCEPT red colour all colours scatter more and vanish before they REACH US . SINCE scattering of red light is very less. It REACHES us . As a result sun appears sun appears reddish during sunrise and sunset. | |
| 3699. |
A piece of stone tied at the end of a thread is whirled in a horizontal circle with uniform speed by hand, Answer the following questions (a) Is the velocity of stone uniform or variable? (b ) Is the acceleration of stone uniform or variable? ( c) What is the direction of acceleration of stone at any instant? (d) which force provides the centripetal force required for circular motion? (e) Name the force and its direction which acts on the hand. |
| Answer» Solution :(a) variable (B) variable (c ) TOWARDS the centre of the circular PATH (d) TENSION in the string (e ) the reaction of tension away from the centre of the circular path | |
| 3700. |
Draw a ray diagram in each of the following cases to show the formation of image, when the object is placed :(i) between optical centre and principal focus of a convex lens.(ii) anywhere in front of a concave lens.(iii) at 2F of a convex lens.State the signs and values of magnifications in the above mentioned cases (i) and (ii). |
Answer» Solution :(i) RAY DIAGRAM is drawn here. The magnification is +ve and has a value greater than 1 (m > 1). It shows that a virtual, erect and enlarged IMAGE is formed. (ii) Ray diagram has been shown here. The magnification is +ve but having a value less than 1 (m < 1). It means that a virtual, erect and diminished image is being formed.  (iii) Ray diagram is drawn here. 
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