What is measurement? Measurement is the process of comparing an unknown quantity with a known quantity. Or, Measurement is expressing characteristics or properties of an object in terms of number and unit. Like expressing length of a table as 1.5 meter, mass of a rice pack as 20 kg etc. Importance of measurement Standardization:- Measurement has made standardization of physical quantities in terms of predefined known quantities possible. This led to a revolution in field of science, technology, medicine, trade and commerce. In the absence of standard quantities the ways of expressing quantities were not uniform. Conficts used to arise while exchanging goods. Quantification:- Measurement helps to quantify unknown quantities. The measured values can be used for fur...

Differences between fundamental quantities and derived quantities Fundamental quantities vs derived quantities. Independent quantities vs dependent quantities. Base quantities vs derived quantities. Base quantities, fundamental quantities and independent quantities terms are used interchangeably. While Derived quantities and dependent quantities terms are used interchangeably. The differences between fundamental and derived quantities are as follows:- Fundamental quantities Derived quantities Those physical quantities which are independent of other quantities are called fundamental or independent quantities. Those physical quantities which dependen upon fundamental quantities for their expression in mathematical form are called derived or dependent quantities. ...

Physics is defined as the scientific study which is concerned with describing the interactions of energy, matter, space, and time, and it is especially interested in what fundamental mechanisms underlie every phenomenon. Applications of physics Knowledge of physics is useful in everyday situations as well as in nonscientific professions. Physics is the foundation of many important disciplines and contributes directly to others. Some applications of physics are as follows:- Engineering :- Most branches of engineering are applied physics. In architecture, physics is at the heart of structural stability, and is involved in the acoustics, heating, lighting, and cooling of buildings. Chemistry :- In chemistry knowledge of physics is required to understand the interactions of atoms and molecules. Biology :- Physics has many applications in the biological sciences. On the microscop...

Solution Input voltage, V₁ = 1200v. Let Number of turns in secondary coil C2 = N₂ Number of turns in secondary coil C1 = N₁ Output voltage = V₂. From question, 1 N₂ =     N₁ 5 N₂ 1      =      N₁ 5 From the transformer ratio, we have N₂ V₂      =      N₁ V₁ V₂ 1 Or,      =      V₁ 5 V₂ 1 Or,          =      1200 V 5  1  240 V Or, V₂ =       1200 V  5  ∴ V₂ = 240 V.  Hence the output voltage will be 240 V.  Laminated core dissipates less amount of heat than a single block of iron core would. Hence laminated core reduces core loss in transformer and incre...

 Medium   Weight  X 12 N Y 18 N Z 14 N Identify water, air and salt solution among X, Y and Z If the weight of 1kg mass in air is 10N, what will be the mass of the given stone? Find the upthrust experienced by the stone? Medium X is "salt solution", medium Y is "air" and medium Z is "water". Solution Given Weight of the stone in air = 18N 1 kg mass in air = 10N. 1N = 1 ÷ 10 kg = 0.1kg So, 18N = 18 × 0.1 kg = 1.8 kg ∴ Weight of the stone = 1.8 kg. Upthrust experienced by the stone in water = 18N - 14N = 4N Upthrust experienced by the stone in salt solution = 18N - 12N = 6N

If both the metal balls are released simultaneously, which one does strike the ground faster? Show with calculation. A person lifts 30kg on the surface of the earth. How much mass can he lift on the surface of the moon if he applies same magnitude of force? In case of the moon :- Given Distance, s = 10 m Acceleration, a = 1.62 m/s² Initial velocity, u = 0 Time, t = ? S = u t + ½ a t² 10 m = 0 × t + ½ × 1.62 m/s² × t² 10 m = 0.81 m/s² × t² t² = 10 / 0.81 s² = 12.346 s² ∴ t =3.514 s In case of the Earth :- Given Distance, s = 10 m Acceleration, a = 9.8 m/s² Initial velocity, u = 0 Time, t = ? S = u t + ½ a t² 10 m = 0 × t + ½ × 9.8 m/s² × t² 10 m = 4.9 m/s² × t² t² = 10 / 4.9 s² = 2.041 s² ∴ t =1.429 s Here from the above calculations it is seen that time in case of the Earth is smaller than in case of the moon. So,...

When we wake up we feel air inside our room cold but if we go out and return to the same room, we feel warm, why? Temperature inside blanket is higher than indoor ambient temperature so when we wake up and came out of blanket then our body came in contact with lower temperature and we feel cold. But outdoor ambient temperature is lower than indoor temperature, so when we went out and returned back to the same room we actually moved to higher temperature zone. That is why we feel warm.

The main reason of energy crisis are as folows:- Over population, Increasing demand, Industrialization, Urbanization, Limited uses renewable sources of energy, Limited stock of non-renewable sources of energy, Misuse of energy and Lack of technology to build machine with efficiency around 100%.

Hydrometer like lactometer, alcoholometer, saccharometer, battery hydrometer, etc. Boats and ships. Flush tank of toilet. Automatic liquid volume indicator.

In a house 6 bulbs each of 100 watt runs for 8 hours daily and 3 heaters of 1500 watt runs for 5 hours daily, how much unit of electricity is consumed in thirty days? Solution Given Bulbs: Number of bulbs, N(Bulbs) = 6 Power of 1 bulb, P(Bulbs) = 100 W Power of 1 bulb in kilowatt, P(Bulbs) = 100/1000 KW = 0.1 KW Time for which it runs daily, T(Bulbs) = 8 hours. Energy consumed by 1 bulb per day in KWh  =  0.1 KW  x 8h = 0.8 KWh Energy consumed by 6 bulbs per day in KWh  = 6 x  0.8 KWh = 4.8  KWh Energy consumed by 6 bulbs in 30 days, E(Bulbs) = 4.8 x 30 KWh = 144 KWh. Heaters: Number of heaters, N(Heaters) = 3 Power of 1 heater, P(Heaters) = 1500 W Power of 1 heater in kilowatt, P(Heaters) = 1500/1000 KW = 1.5 KW Time for which it runs daily, T(Heaters) = 5 hours. Energy consumed by  1 heater  per day in KWh  =  1.5 KW  x 5h = 7.5 KWh Energy consumed by 3  heaters  per day in KW...

    Step-down transformer     The reason is because 240 volts is stepped down to a lower voltage of 12 volts.

Solution Given Current drawn by electric bulb, I bulb   =  0.8 A Voltage supplied to the electric bulb, V bulb   =  220 V Time duration of use of bulb per day, T day   =  8 hours Time duration of use of bulb in a month, T month   =  8*30 hours                     = 240 hours Power rating of electric bulb, P bulb   =  I bulb * V bulb             = 0.8 A * 220 V = 176 watts Energy consumed by bulb in a month, E bulb   =  P bulb *T month                     =  176 W * 240 hours = 42,240 watt-hours Energy consumed by bulb in a month in terms of KWh, E bulb,KWh ...

Filament bulb uses fine tungusten(W) coil as filament which emits white light at 3000⁰C. At this high temperature tungusten reacts with oxygen called oxidation of tungusten . This results in thinning of tungusten filament and eventually breaks after some hours of working.

Solution Given Numbers of tube lights, N tube   =  10 Power rating of each tube light, P tube   =  20 W Time duration of use of each tube light per day, T day   =  5 hours Time duration of use of each tube light in a month, T month   =  5*30 hours                     = 150 hours Energy consumed by each tube light in a month, E tube   =  P tube *T month                     =  20 W * 150 hours = 3000 watt-hours Energy consumed by each tube light in a month in terms of KWh, E tube,KWh   =  E tube /1000                     =...

Give reasons Displacement is a vector quantity.               Displacement is a vector quantity because it has both magnitude and direction. Speed is a scalar quantity.               Speed is a scalar quantity as it has only magnitude no direction. Average speed is same as the actual speed in case of a body having uniform motion.               A body moving with uniform motion has its speed constant. The distance covered by a uniformly moving body every second is constant. So a verage speed is same as the actual speed in case of a body having uniform motion. An artificial satellite goes around the earth in a perfect circular orbit with constant speed.               An artificial satellite going around the earth is constantly pulled by the earth. To overcome this centripetal force a centrifugal force is required. So artificial sat...

Differentiate between distance and displacement. distance vs displacement.                     Distance                   Displacement Distance is the actual length of the path covered . Displacement is the shortest distance between two points. It is a scalar quantity . It is a vector quantity . It has magnitude but no direction . It has both magnitude and direction . It is always positive . It can be positive, zero or negative . It is used for calculating speed . It is used for calculating velocity .

Differentiate between scalar quantity and vector quantity. scalar quantity vs vector quantity.                 Scalar Quantity                   Vector Quantity It has only magnitude . It has both magnitude and direction . Problems of scalar quantities are solved by simple rules of algebra . Problems of vector quantities are solved by rules of vector algebra . Sum of scalar quantities is always positive . Sum of vector quantities can be positive, zero or negative . It is denoted by normal letters . It is denoted by an arrow or bold letters .

Differentiate between gravity and acceleration due to gravity. gravity vs acceleration due to gravity.                       Gravity           Acceleration due to gravity Gravity is a force . Acceleration due to gravity is acceleration . Its SI unit is Newton . Its SI unit is m/s 2 . Gravity is a force of attraction between the earth and a body. The acceleration attained by a freely falling body under the influence of gravity is called acceleration due to gravity. Gravity is a cause . Acceleration due to gravity is an effect . As per Newton’s universal law of gravitation Gravity at a point R...

Differentiate between mass and weight. mass vs weight. The differences between mass and weight are as follows :- Mass Weight The amount of matter contained in a body is called its mass. The force with which a body is attracted toward the centre of a celestial body is called weight of the body at that place. Mass of a body remains constant. Weight of a body varies with place. Mass is a fundamental quantity. Weight is a derived quantity. Mass is a scalar quantity. Weight is a vector quantity. Mass of a body can’t be zero. Weight of a body can be zero. Mass is measured using beam balance. Weight is measured using spring balance or top balance. S.I. unit of mass is Kg. S.I. Unit of weight is Newton (N). CGS un...