Answer:
The potential difference between the ends of a wire is 60 volts.
Explanation:
It is given that,
Resistance, R = 5 ohms
Charge, q = 720 C
Time, t = 1 min = 60 s
We know that the charge flowing per unit charge is called current in the circuit. It is given by :
I = 12 A
Let V is the potential difference between the ends of a wire. It can be calculated using Ohm's law as :
V = IR
V = 60 Volts
So, the potential difference between the ends of a wire is 60 volts. Hence, this is the required solution.
Answer:
Resistivity 
It depends upon cross sectional area and length of material
Explanation:
The resistance of any material is given by
, here
is the resistivity of material , l is length of material and A is cross sectional area
So resistivity 
So resistuivity of any material depends upon area of cross section and length of material
If cross sectional area will be more then resistivity will be more. And is length of the material will be more then resistivity will be less
Answer:
The reactance of the capacitor
Explanation:
In an AC circuit containing different elements (capacitors, resistors and inductors), we cannot simply calculate the equivalent resistance of the circuit, so another quantity is used, which is called reactance.
For a capacitor, the reactance is given by:

where:
f is the frequency of the AC current in the circuit
C is the capacitance of the capacitor
The reactance has a similar meaning to that of the resistance for a DC current. In fact, we notice that:
- When f=0 (which means we are in regime of DC current, because the current never changes direction), the reactance is infinite. This is correct: in a DC circuit, the capacitor does not let current pass through it, so it like it has infinite resistance (=infinite reactance)
- When f tends to infinite, the reactance becomes zero: in such situation, the current in the circuit changes direction so quickly that the capacitor has no enough time to "block" the current in the circuit, so it like it has almost zero resistance (zero reactance).
Answer : 2446 years.
Explanation :
Length of semi major axis is, 
According to Kepler's third law, square of time period of an orbit is directly proportional to the cube of the semi major axis.
i.e 
where G is gravitational constant
M is mass of sun, 
So, 




since, 
So, orbital period is approximately 2446 years.
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