Answer:
Part A: 16.1 V
Part B: 20.5 V
Part C: 21.5%
Explanation:
The voltmeter is in parallel with the 4.5-kΩ resistor and the combination is in series with the 6.5-kΩ resistor. The equivalent resistance of the parallel combination is given as


Part A
The voltmeter reading is the potential difference across the parallel combination. This is found by using the voltage-divider rule.

Part B
Without the voltmeter, the potential difference across the 4.5-kΩ resistor is found using the same rule as above:

Part C
The error in % is given by

Answer with Explanation:
We are given that
Weight of an ore sample=17.5 N
Tension in the cord=11.2 N
We have to find the total volume and the density of the sample.
We know that
Tension, T=
=buoyancy force
T=Tension force
W=Weight
By using the formula

N

Where
=Volume of object
=Density of water
=Acceleration due to gravity
Substitute the values then we get


Volume of sample=
Density of sample,
Where mass of ore sample=1.79 kg
Substitute the values then, we get

Density of the sample=
<span>Because they occur at an atomic level, changing the actual structure of the thing.
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The resistance of the cylindrical wire is
.
Here
is the resistance,
is the length of the wire and
is the area of
cross section. Since the wire is cylindrical
.
Comparing two wires,

Dividing the above 2 equations,

Since 
The above ratio is

We also have,

The current through the Silver wire will be 4.23 times the current through the original wire.