potential energy of a spring if it is compressed to a distance x from its mean position i
B Very Short Questions
kinetic
(Spring constant is k)
(b) Watt-second
(d) Kilowatt per hour
(a) kx
y can
(c) kx2
1r?
light
(d) None of these
1. Define work and write its unit.
2. What is energy? Write its unit.
3. What do you understand by kinetic energy?
4. What is potential energy?
5. Explain the law of conservation of energy.
6. Write the various forms in which energy is dissipated.
7. Is it possible to construct a system having 100% efficiency?
8. What do you understand by electrical energy?
9. Write the name of any three electrical appliances.
10. What is power? Write unit of power.
11. Which type of lighting should be used in homes to reduce the electricity consumption?
12. What should be taken in consideration while purchasing new domestic electrical applian
13. A body gets displaced by 10 m when a force of 20 N acts on it. Find out the work done.
[Ans. 200 Jules)
14. A body of mass 30 kg is lifted to a height of 2 m in 1 minute. Calculate the power (g = 1
k
Answers
Explanation:
An algebraic expression in mathematics is an expression which is made up of variables and constants, along with algebraic operations (addition, subtraction, etc.). Expressions are made up of terms.
Answer:
1.)Power is defined as work done per unit time.
...
What is Work, Energy and Power?
Work
Definition Work is said to be done when a force applied to an object moves that object.
Formula We can calculate work by multiplying the force by the movement of the object. W = F × d
Unit The SI unit of work is the joule (J)
2.Energy is the capacity of a physical system to do work. The common symbol for energy is the uppercase letter E. The standard unit is the joule, symbolized by J. One joule (1 J) is the energy resulting from the equivalent of one newton (1 N) of force acting over one meter (1 m) of displacement.
3.Kinetic energy, form of energy that an object or a particle has by reason of its motion. ... Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass.
4.the form of energy that an object gains as it is lifted.
5. In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. ... For systems which do not have time translation symmetry, it may not be possible to define conservation of energy.
6.Heat energy is the most easily dissipated form of energy. Light energy is frequently energy seen in combustion, and is a type of wave motion. Sound energy is another type of wave motion caused by the vibration of molecules in the air. Like heat energy, sound is a type of energy that is generally lost.
7.making it clear that an efficiency of 1, or 100%, is possible only if there is no heat transfer to the environment (Qc=0).
8.Electrical energy is energy derived from electric potential energy or kinetic energy. ... Thus, all electrical energy is potential energy before it is delivered to the end-use. Once converted from potential energy, electrical energy can always be called another type of energy (heat, light, motion, etc.).
9.Appliances are divided into three types: small appliances; major appliances, or white goods; and consumer electronics, or brown goods.
...
Home appliance
Wheels In some cases
Examples Refrigerator, toaster, kettle, microwave,
10. In physics, power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second.
SI unit: watt (W)
In SI base units: kg⋅m2⋅s−3
Derivations from other quantities: P = E/t; P = F·v; P = V·I; P = τ·ω
11.Light Emitting Diode (LED ) are emerging as the most energy-efficient source of lighting, with a LED bulb using 1/10th as much energy as a normal incandescent bulb and half as much energy as a Compact Fluorescent Lamp (CFL) to produce the same amount of light.
12.Buy the right sized appliance as per your requirement. Do not buy oversize refrigerator or AC or Washing machine if you do not require them. Larger is the appliance higher is the energy consumption and bills. Think of the long term advantage while buying home appliances.
13. Here, force=20N and displacement=10m
Work=Force×Displacement=20N×10m=200Nm
14.
W=F×s=mgh
=30×10×50=15000
Work done =15×10
3
joule