For a point charge, how does the potential vary with distance from the point charge, r?
a constant
b. r.
c. 1/r.
d.
.
e.
.
Answer:
The correct option is C
Explanation:
Generally for a point charge the electric potential is mathematically represented as

Here we can deduce that the electric potential varies inversely with the distance i.e

So
Answer:
Correct option a. one state variable T.
Explanation:
In the case of an ideal gas it is shown that internal energy depends exclusively on temperature, since in an ideal gas any interaction between the molecules or atoms that constitute it is neglected, so that internal energy is only kinetic energy, which depends Only of the temperature. This fact is known as Joule's law.
The internal energy variation of an ideal gas (monoatomic or diatomic) between two states A and B is calculated by the expression:
ΔUAB = n × Cv × (TB - TA)
Where n is the number of moles and Cv the molar heat capacity at constant volume. Temperatures must be expressed in Kelvin.
An ideal gas will suffer the same variation in internal energy (ΔUAB) as long as its initial temperature is TA and its final temperature TB, according to Joule's Law, whatever the type of process performed.
Answer:
F = 0.332 N in the east direction
Explanation:
Length, L = 7.7 cm = 7.7 * 0.01 = 0.077 m(along the north south)
Current, I = 3.45 A (northwards)
Magnetic field, B = 1.25 T (vertically upwards)
The magnitude of the force is given by, F = ILBsin90
F = 3.45 * 0.077 * 1.25 * 1
F = 0.332 N
The direction of the force is calculated using the Right Hand Thumb Rule:
It states that "Hold the wire carrying current in your right hand so that the thumb points along the wire in the direction of the current, then the fingers will encircle the wire in the direction of the lines of magnetic force."
Based on the Right Hand Thumb Rule, the magnetic force will act in the east direction