16. Current Of Electricity

Question 1

What is electric charge Q? (and formula)

Answer 1

The electric charge Q passing a point in a circuit in an interval of time t is given by ΔQ=I Δt for a constant electric current I in a circuit.

Question 2

What is Electric Current I ?

Answer 2

Electric current (I) is the rate of flow of charge. I = Q/t

Question 3

What is I = nAvq ?

Answer 3

current = number density of charge carriers (n) ✖️ cross sectional area (A) ✖️ drift velocity (v) ✖️ charge (q)

Question 4

What is Potential Difference (V)?

Answer 4

The potential difference (V) between two points in a circuit is the energy per unit charge converted from electrical energy to other forms of energy when charge passes from on point to another.

Question 5

what is the formula of potential difference?

Answer 5

potential difference (V) = electrical energy (W) / charge flow (Q)

Question 6

what direction current flow in ?

Answer 6

it flows from a region of higher potential to lower potential.

Question 7

What is resistance?

Answer 7

The resistance (R) of a circuit component is the ratio of the potential difference across it to the current flowing through it.

Question 8

What is the formula of resistance?

Answer 8

resistance (R) = potential difference across the conductor (V) / the current flowing through the conductor (A)

Question 9

What is resistivity?

Answer 9

Resistivity is the ability of the material to inhibit flow of an electrical current.

Question 10

What is the formula of resistance? (resistivity)

Answer 10

resistance (R) = resistivity of material (𝛒) ✖️ length of material (L) / cross sectional area of material (A)

Question 11

What is Ohm’s Law?

Answer 11

Ohm’s law states that the current flowing in a metallic conductor is proportional to the potential difference applied across it, provided that the physical conditions are constant.

Question 12

What is the formula of power?

Answer 12

power (P) = electrical energy (W) / time (t) = charge (Q) ✖️ potential difference(V) / time (t)

Question 13

What are the other formulas of power? (sub v=ir)

Answer 13

P= I²R or P=V²/R

Question 14

What is electromotive force (e.m.f) ?

Answer 14

The electromotive force (e.m.f) of a source is the energy converted per unit charge from other forms of energy into electrical energy when charge is moved round a complete circuit.

Question 15

What is the formula of e.m.f ?

Answer 15

e.m.f (E) = electrical energy converted (W) / charge (Q)

Question 16

What is the difference between e.m.f and p.d?

Answer 16

e.m.f is the amount of other energy converted to electrical energy whereas potential difference is the amount of electrical energy converted to other forms of energy.