The density of the block is 1.25 cm³
The correct answer to the question is Option B. 1.25 cm³
To solve this question, we'll begin by calculating the volume of the block. This can be obtained as follow:
Length = 7 cm
Height = 4 cm
Width = 3 cm
<h3>Volume =? </h3>
Volume = Length × Width × Height
Volume = 7 × 3 × 4
<h3>Volume = 84 cm³</h3>
Thus, the volume of the block is 84 cm³
Finally, we shall determine the density of the block. This can be obtained as follow:
Density is defined as mass per unit volume i.e

Mass of block = 105 g
Volume of block = 84 cm³
<h3>Density of block =? </h3>

<h3>Density of block = 1.25 cm³</h3>
Therefore, the density of the block is 1.25 cm³.
Hence, Option B. 1.25 cm³ gives the correct answer to the question.
Learn more: brainly.com/question/2040396?referrer=searchResults
The correct answer to the question is A) Electrons.
EXPLANATION:
The electrical conductivity of a metal or any substance depends on the free electron concentration of the metals.
Free electrons are those electrons which are present in the conduction band of the metals. These electrons experience less amount of force attraction from the nucleus. Protons and neutrons do not contribute anything to the current conduction in a metal.These sub atomic particles are bound to the nuclei of atoms.
When we maintain potential difference across the two ends of a conductor, the free electrons are drifted towards the positive terminal of the battery.
Hence, electrical conductivity of a substance is the ability of the electrons to move inside the substance.
More is the conductivity of the substance, the lesser is the resistance to the flow of electrons inside the substance, and vice versa.
B low frequency it is the lowest frequency
1. Amperes, is the SI unit (also a fundamental unit) responsible for current.
2.
Δq over Δt technically
Rearrange for Δq
I x Δt = Δq
1.5mA x 5 = Δq
Δq = 0.0075
Divide this by the fundamental charge "e"
Electrons: 0.0075 / 1.60 x 10^-19
Electrons: 4.6875 x 10^16 or 4.7 x 10^16
3. So we know that the end resistances will be equal so:
ρ = RA/L
ρL = RA
ρL/A = R
Now we can set up two equations one for the resistance of the aluminum bar and one for the copper: Where 1 represents aluminum and 2 represents copper

We are looking for L2 so we can isolate using algebra to get:

If you fill in those values you get 0.0205
or 2.05 cm
Answer:
Total Energy consumed = 146.94 kwh
Total cost = rs 587.76
Explanation:
Given:
3 bulbs each 60 watt [for 3 hours daily]
4 fans each 100 watt [for 8 hours daily
1 electric heater of 2 kWh (2,000 watt) [for half hour daily
]
Rate = rs 4/Kwh
Find:
Total Energy consumed
Total cost
Computation:
Energy used = Power × time
3 bulbs each 60 watt [for 3 hours daily] = 3 x 60 x 3 x 31 = 16,740 watt = 16.74 kw
4 fans each 100 watt [for 8 hours daily = 4 x 100 x 8 x 31 = 99,200 watt = 99.2 kw
1 electric heater of 2 kWh [for half hour daily
] = 1 x 2000 x (1/2) x 31 = 31,000 watt = 31 kw
Total Energy consumed = 16.74 + 99.2 + 31
Total Energy consumed = 146.94 kwh
Total cost = 146.94 x 4
Total cost = rs 587.76