Circuits

Question 1

Current exists whenever…

Answer 1

there is a net flow of charge (not an electrostatic equilibrium).

Question 2

DC Current from…

Answer 2

batteries.

Question 3

SI unit of current

Answer 3

Ampere

Question 4

By convention, the direction of current is…

Answer 4

The direction of the flow of positive charge.

Question 5

Charge carriers: Positive or negative?

Answer 5

Negative

Question 6

Current

Answer 6

The electrons in a conductor move in response to an electric field in the conductor.

Question 7

vd

Answer 7

drift speed.

Question 8

drift speed dependent on many parameters, most notably

Answer 8

temperature

Question 9

At a higher temperature, the drift speed…

Answer 9

decreases - more collisions.

Question 10

sigma

Answer 10

conductivity of metal.

Question 11

rho =

Answer 11

1/sigma

Question 12

Ohmic material

Answer 12

Resistance curve is linear.

Question 13

Kirchoff’s Rules for Circuits

Answer 13

Conservation of charge: junction rule. Conservation of energy: loop rule.

Question 14

Conservation of charge: junction rule

Answer 14

I in = I out (sums)

Question 15

Conservation of energy: loop rule

Answer 15

The sum of the potential differences across all the circuit elements in a closed loop must be zero.

Question 16

Power

Answer 16

Rate of energy transformation.

Question 17

Units of power

Answer 17

Watt

Question 18

Watt

Answer 18

Joules/Second

Question 19

Series

Answer 19

Two circuit elements are said to be connected in series if the current, passing through one, has no option but to pass through the other.

Question 20

Parallel

Answer 20

Two circuit elements are said to be connected in parallel if both their sides are connected with no intervening circuit elements.