Chapter 10 - Electrical circuits

Question 1

Kirchhoff’s second law and what is it a result of

Answer 1

In any circuit the sum of the p.d.’s is equal to the sum of the emf’s, it’s a result of the conservation of energy

Question 2

Behavior of a current in a series circuit

Answer 2

The same everywhere

Question 3

Behavior of p.d. in a series circuit

Answer 3

split across each component so that the sum of the p.d.’s in the components equals the emf.

Question 4

Resistance in a series circuit

Answer 4

R1 + R2 + R3 = Rtotal

Question 5

Resistance in a parallel circuit

Answer 5

1/R1 + 1/R2… = 1/Rtotal

Question 6

Current in a parallel circuit

Answer 6

Current in each loop adds up to the total current

Question 7

p.d. in a parallel circuit

Answer 7

split across components in the loop

Question 8

Define internal resistance

Answer 8

Some energy transferred to the charge carriers is lost to the internal resistance of the cell, through heat etc.

Question 9

Equation with internal resistance

Answer 9

e.m.f = I(R+r) where Ir is the lost volts (the difference between emf and pd’s)

Question 10

In a series circuit, how does the p.d. split

Answer 10

proportional to the resistance of each component

Question 11

Equations for potential divider

Answer 11

V1/V2 = R1/R2
V1/R1 = V2/R2
V(out) = R2/(R1+R2) x V(in)
where v out is the p.d. and v in is the e.m.f.