EE1F25- Basic laws and terminologies

Question 1

What is a circuit?

Answer 1

Interconnection of elements forming a closed path along which current can flow.

Question 2

How does current and electrons flow in a circuit?

Answer 2

Current flows from positive to negative and electrons flow from negative to positive.

Question 3

What are active elements?

Answer 3

Energy producing elements such as batteries, generators and solar cells.

Question 4

What are passive elements?

Answer 4

Energy using elements such as capacitors.

Question 5

Define:
Voltage-
Current-
Ohm-

Answer 5

Voltage- pressure that triggers electron flow
Current- rate of electron flow
Ohm- opposition to the flow of electrons

Question 6

What is ohms law?

Answer 6

V=IR ; establishes the relationship between voltage current and resistance (current is directly proportional to voltage given constant physical conditions)

Question 7

What is voltage drop?

Answer 7

Any time a voltage drives a current through a resistor some of the voltage drops across the resistors, the magnitude of which is determined by the product of current and resistance.

Question 8

What is kirchoff’s current law?

Answer 8

The sum of all currents entering a node is equal to the sum of the current leaving a node.

Question 9

What is Kirchoff’s voltage law?

Answer 9

The algebraic sum of the voltage in a loop equals zero, sum of emfs is equal to potential dropped in a closed circuit.

Question 10

Define:
Node (junction)-
Path-
Branch-
Loop/Mesh-

Answer 10

Node- A point where current splits or joins together
Path- Any connection where current flows
Branch- Path between two nodes
Loop/mesh- Close path of a circuit

Question 11

Define a short-circuit?

Answer 11

Branch of theoretically zero resistance, it diverts itself to all currents that would have flown in adjacent branches, (branches hooked to the same node) except branches with sources/ diverts all the current to itself through least path of resistance.

Question 12

Define open circuit?

Answer 12

A branch with theoretically infinite resistance, prevents current flowing in its branch.

Question 13

Define impedance?

Answer 13

The opposition to current flow in a circuit owing to the presence of combinations of resistive, inductive and capacitive reactance.

Question 14

What is the phase relation between current and voltage in a capacitor?

Answer 14

The current in a capacitor leads the voltage by 90 degrees.