Direct current (DC) is the flow of electric charge in only one direction. It is the steady state of a constant-voltage circuit. Most well-known applications, however, use a time-varying voltage source. Alternating current (AC) is the flow of electric charge that periodically reverses direction.
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<em>#</em><em>L</em><em>E</em><em>T</em><em>S</em><em> </em><em>STUDY</em></h2>
Answer/solution:
Given :
Mass =5kg
T 1 =20 C,T 2 =100 ∘C
ΔT=100−20=80 ∘C
Q=m×C×ΔT
where C= specific heat capacity of water
=4200J/(kgK)
Q=5×4200×80
=1680000 Joule.
=1680KJ
The correct options are:
1 How tall are you?
2How far is it from your house to your school?
3How wide is your refrigerator?
All these measurements involve to measure a length. Instead, the other two options involve to measure different physical quantities; for instance, the question
4 How much does your sister weigh?
Involve to measure a weight (and so, a mass), while the question
5 How warm is it in San Diego?
requires to measure a temperature.
The net force on an object subject to friction is equal to the sum of the applied force and the frictional force.
Mathematically,
Here, m is mass of object and a is its acceleration. We take frictional force negative because it opposes the motion of object.
Given, 
, 
and 
Substituting these values in above formula, we get
.
Thus, the acceleration of an object is 
