LDR EXAMINATION 2026 VERIFIED
SOLUTION COMPENDIUM
◉What happens to the potential difference across the LDR when it is
exposed to bright light? Answer: The potential difference becomes
very low because its resistance is low
◉Why does the lamp light up brightly when the LDR is in the light?
Answer: The LDR has low resistance, allowing more potential
difference to the lamp
◉What happens to the potential difference across an LDR in a series
circuit when it is placed in darkness? Answer: The potential
difference becomes very high because its resistance rises sharply
◉Why does the lamp become dim when the LDR is in darkness?
Answer: The LDR has high resistance, taking most of the potential
difference
◉Provide a real-world example of how an LDR is used in a mobile
phone. Answer: It detects when the phone is held to an ear,
switching the screen off to save battery
SOLUTION COMPENDIUM
◉What happens to the potential difference across the LDR when it is
exposed to bright light? Answer: The potential difference becomes
very low because its resistance is low
◉Why does the lamp light up brightly when the LDR is in the light?
Answer: The LDR has low resistance, allowing more potential
difference to the lamp
◉What happens to the potential difference across an LDR in a series
circuit when it is placed in darkness? Answer: The potential
difference becomes very high because its resistance rises sharply
◉Why does the lamp become dim when the LDR is in darkness?
Answer: The LDR has high resistance, taking most of the potential
difference
◉Provide a real-world example of how an LDR is used in a mobile
phone. Answer: It detects when the phone is held to an ear,
switching the screen off to save battery
