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Five point charges each of charge q are placed on five vertices of a regular hexagon of side l .Find the magnitude of resultant force on charge -q placed at center of hexagon

Out of 5 vertices

4 vertices forces will cancel each other

as distance from center = same but direction is opposite

so only force will be from the vertices , opposite to which no charge

F = k q(q)/l²

Force will be attractive in nature as opposite charges

The speed of sound is determined by the medium in which it is traveling, and therefore is the same for a moving source. The Doppler effect is observed whenever the source of waves is moving with respect to an observer. The Doppler effect - an apparent shift in frequency for a sound wave produced by a moving source.

An expression for apparant frequency of sound:

(1) When both Source and listener approaching each other f' = [(v - vo)/((v + vs)]f

(2) When both Source and listener moving away from each otherf' = [(v - vo)/((v - vs)]f

TheDoppler effect(or theDoppler shift) is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. A common example ofDoppler shiftis the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer.

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option B is the correct answerbeats are formed by constructive interfarance of two and more waves(which have different frequencies)

In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.

Hitting two utensils against each other produces sound.

Option (c) is correct.

the lowest temperature that is theoretically possible, at which the motion of particles which constitutes heat would be minimal. It is zero on the Kelvin scale, equivalent to −273.15°C..

Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as 0.

canal rays rae positively charged radiations that can pass through perforated cathode plate, These rays consist of positively charged particles known as protons.

1) It is well known that the resistance of a material varies with temperature. Variable which represents this variability of resistance is defined as temperature coefficient of resistance.

The resistance-change factor per degree Celsius of temperature change is called the temperature coefficient of resistance. This factor is represented by the Greek lower-case letter “alpha” (α). A positive coefficient for a material means that its resistance increases with an increase in temperature where as a negative coefficient means that resistance decreases with an increase in temperature.

The electrical resistance of conductors such as silver, copper, gold, aluminum etc., depends upon collusion process of electrons with in material. As the temperature increase, this electron collusion process becomes faster, which results in increased resistance with rise in temperature of conductor. This property of materials which increase the kinetic energy of molecules is represented as temperature coefficient of resistance.

2) The emf (electromotive force) is the the potential difference between the terminals of a battery when no current is flowing through an external circuit when the circuit is open.Potential difference is the voltage across the terminals of the battery when the current is being drawn from it to an external.

floats on water due to surface tension.

Commercial unit of energyis the kilowatt-hour (kWh). TheSI unit of energyis the Joule (J).

The relation between kilowatt hour and joule is..1 kWh = 3,600,000 J

And

1 kWh = 3·6 MJ (mega joules)

The split ring in the electric motor also known as a commutator reverses the direction of current flowing through the coil after every half rotation of the coil. Due to this the coil continues to rotate in the same direction.

Heat capacity = Mass × Specifc heat capacity= 150 × 10^-3 kg × 410 J / (kg K)= 61.5 J / K

Heat capacity of copper is 61.5 J/K

Nichrome wire will get heated up quickly because its an alloy and has properties of high resistance. Also it can be seen as a real life example that copper wire are preferred to be made into wire rather using some other material.

DynamosandGeneratorsconvert mechanical rotation intoelectricpower.Dynamo- a device that makes direct currentelectricpower using electromagnetism. It is also known as agenerator,

It works on the principle of electromagnetism.

Force applied by team A = 100 + 115 + 125 = 340 n.

Force applied by team B = 105 + 128 + 107 = 340 n.

So, resultant force = 340 - 340 = 0.

100_25(due to going in West)=75

A car travels 100m due east and 25m due west.a) what is the distance covered by the car :

Distance is the total path covered by the object.hence distance travelled=100+25=125mb)what is its displacement?

Displacement is the shortest path between source and destination.Car moves 100m forward(east) and then 25m backward(west)so displacement=100-25=75m

HEY!!

The distance will be = 100 + 25 = 125m

A = 100 m on east from west and again east to west = 25m

Displacement = 100 - 25 = 75 m.

distance=100+25=125mdisplacement=100-25=75m

Ans 100+25= 125

100-25=75so Distance =125Displacement =75

Distance travelled towards east = 40m/h * 1 hr = 40m

Distance travelled towards north = 30m/h * 1 hr =30m

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Displacement vector will be the hypotenuese if we draw the triangle.

Hence displacement = root of ( 40^2 + 30^2) = 50m

.Total time taken to reach the final point = 1hr east + 1hr north = 2 hrs

Average velocity = 50m / 2 hrs =25m/hr

MYOPIAor NEARSHIGHTED.Myopiaoccurs when the eyeball is toolong, relative to the focusing power of the cornea and lens of the eye.

HYPEROPIAor FARESIGHTED. Thisvision problemoccurs when light rays entering the eye focus behind the retina, rather than directly on it.

ASTIGMATISM.

PRESBYOPIA.

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circle circumference will have same resistance as beforeso

Centripetal acceleration:If an object moves in a circle it changes its velocity i.e. it is accelerating. This acceleration is known as the centripetal acceleration.or we can say that the centripetal acceleration is defined as the rate of change of tangential velocity.Now we know that, the centripetal force required to keep a particle of mass ‘m’ revolving in a circular path of radius ‘r’ with a speed ‘v’ is,F = mv2/rNow, centripetal acceleration (ac) is the radial acceleration due to the centripetal force.Using,ac= F/m=> ac= [mv2/r]/m=> ac= v2/rThe centripetal acceleration is directed along the radius in the circular motion.

Inphysics, thekinetic energyof an object is theenergythat it possesses due to itsmotion.It is defined as theworkneeded to accelerate a body of a given mass from rest to its statedvelocity. Having gained this energy during itsacceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body when decelerating from its current speed to a state of rest.Common symbols

KE,Ek, or TSIunit joule(J)Inclassical mechanics, the kinetic energy of a non-rotating object .object ofmassmtraveling at aspeedvis1/2 mv^2 Inrelativistic mechanics, this is a good approximation only whenvis much less than thespeed of light.The standard unit of kinetic energy is thejoule.

energy gives us capacity to do work

Rajendra prasad

Volt is the SI unit of electromotive force, the difference of potential that would carry one ampere of current against one ohm resistance.

Lavoisier named carbon.Please hit the like button if this helped you

This is known hypermetropia. Hypermetropia is also known as far sightedness.

The causes are :

1. this defect arises because of the focal length of the eye lens to long.

2. the eyeball has become too slow.

this can be corrected by using a convex lens of appropriate power.

Crop only the question that you want a solution for. We will not be able to provide solutions to multiple questions.

Here, it should be noted that rise in Celsius scale is equal to rise in Kelvin scale. This is because both the scales have 100 divisions and size of each division is same for both. Thus if temp increased by 15 divisions on Celsius scale corresponding rise would be same on Kelvin scale. Hence the answer: 15 K

Gram atomic massis themass, ingrams, of one mole ofatomsin a monatomic chemical element. It is numerically equal to the relativeatomic mass(oratomic weight) ingrams. Theatomic massof an element expressed ingramsis calledgram atomic mass. For example oxygen is 16grams

Gram molecular massis themassingramsof one mole of amolecularsubstance

The moment of inertia depends not only on themassof an object, but also on its distribution ofmassrelative to the axis around which it rotates.

5root3/2m...................

section formula for external division

section formula of external Division is the correct answer of the given question

“A device used to convert heat energy into work is called a heat engine”. It extracts heat Q1 from the source and rejects a heat Q2 to the sink Efficiency, 2111w QQ Ql η = =−