Module 4 - 4.2.3 Resistance

Question 1

Ohm’s Law

Answer 1

The current through a conductor is directly proportional to the p.d. across it provided that physical conditions remain constant

Question 2

Fixed Resistor

Answer 2

• ohmic
• resistance stays constant

Question 3

Bulb

Answer 3

• as p.d. increases, bulb gets hotter
• as bulb gets hotter, resistance increases

Question 4

Thermistor (heat) and LDR (light)
- resistance
- energy

Answer 4

• as temp/light intensity increases, resistance decreases
• as more energy is put in, more electrons can take part in conduction

Question 5

Diode

Answer 5

• only lets current go in the “forward” direction

Question 6

Advantages of LEDs (6)

Answer 6

• more efficient
• more versatile
• pretty robust
• operate at low potentials
• switch on instantly
• have longer working lives