Answer:
answer is friction. MCQ A is answer
Answer:
a = 0.55 m / s²
Explanation:
The centripetal acceleration is given by the relation
a = v² / r
angular and linear velocities are related
v = w r
we substitute
a = w² r
In the exercise they indicate the angular velocity w = 1 rev/min, let's reduce to the SI system
w = 1 rev / min (2pi rad / 1rev) (1min / 60s) = 0.105 rad/ s
let's calculate
a = 0.105² 50.0
a = 0.55 m / s²
Parallel circuit
Advandages: 1. Every unit that is connected in a parallel circuit gets equal amount of voltage.
2. It becomes easy to connect or disconnect a new element without affecting the working of other elements.
3. If any fault happened to the circuit, then also the current is able to pass through the circuit through different paths.
Disadvantages: 1. It requires the use of lot of wires.
2. We cannot increase or multiply the voltage in a parallel circuit.
3. Parallel connection fails at the time when it is required to pass exactly same amount of current through the units.
series circuit
Advantages: 1. Series circuits do not overheat easily. This makes them very useful in the case of something that might be around a potentially flammable source, like dry plants or cloth.
2. Series circuits are easy to learn and to make. Their simple design is easy to understand, and this means that it’s simple to conduct repairs .
3. we can add more power devices, they have a higher output in terms of voltage .
4. The current that flows in a series circuit has to flow through every component in the circuit. Therefore, all of the components in a series connection carry the same current.
Disadvantages: 1.If one point breaks in the series circuit,the total circuit will break.
2. As the number of components in a circuit increases ,greater will be the circuit resistance.
Answer:
Explanation:
We can find the resistance of the wire by using Ohm's law:
where
V is the voltage applied
R is the resistance
I is the current
In this problem, we know I = 6 A and V = 68 V, so we can re-arrange the equation to find the resistance of the wire:
Answer:
metal> metalloids >nonmetals (Electrical conductivity)
Explanation:
Electrical conductivity of objects can be compared by the bonding energy of electrons in them.
Metals have less bonding energy of electrons, so even at room temperature their are significant number of free electrons to carry electrical current.
Nonmetals have a very high bonding energy of electrons, so at room temperature negligible number of free electrons are present so electrical conductivity is very low.
Metalloids have both metallic and non metallic features. The electron bonding energy falls in between that of metals and nonmetals. So electrical conductivity also lies in between metals and nonmetals.
