Answer:
The answer is True.
Explanation:
Open circuit means incomplete flow of current in a circuit.
When switch is off, the electric current cannot flow throught the circuit for a complete circuit.
Answer:
1. A substance that can be separated into two or more substances only by a chemical change is a(n) _____.
solution
element
mixture
compound
2.
Which of the following materials is a substance?
air
gasoline
stainless steel
silver
3.
The first figure in a properly written chemical symbol always is _____.
boldfaced
capitalized
italicized
underlined
4.
Which of the following represents a compound?
H
H-3
H2O
O-16
5. What do chemical symbols and formulas represent, respectively?
elements and compounds
atoms and mixtures
compounds and mixtures
elements and ions
Explanation:
Answer:
A )
Explanation:
This change in frequency observation occur due to doppler effect
if the wave source moves,In the time between one wave peak being emitted and the next, the source will have moved so that the shells will no longer be concentric. The wavefronts will get closer together in front of the source as it travels and will be further apart behind it. (see the graph)
when the person standing still in front of the ambulance, he will observe a <em>higher frequency </em>than before as the source travels towards them.

The pitch we hear depends on the frequency of the sound wave.
A high frequency corresponds to a high pitch
as we hear a higher frequency , it makes the <em>pitch higher</em> too
Answer:
The right option is C. i.e L
Explanation:
Dimension of a quantity is the collection of the indexes of each of the fundamental quantities contained in it.
Therefore, to get the dimension of A in the equation
X=Asin(2(pi)ft)
Making A the subject of the formula
A = X / (sin(2(pi)ft)
Since sin(2(pi)ft which is a trigonometric function does not have a dimension
A = L
The dimension of A is L