Radiology · single question
If we INCREASE the exposure time during X-ray, what would happen?
Show answer and explanation
Correct answer: A. Increase the QUANTITY (number) of electrons
Increase the QUANTITY (number) of electrons — and therefore photons (A). In dental X-ray physics:
• Exposure TIME: affects the QUANTITY (number) of X-rays/photons produced. Longer time = more electrons flow across the tube = more X-ray photons = denser/darker image.
• mA (milliamperage): also controls quantity — it determines the rate of electron flow (tube current).
• kVp (kilovoltage peak): controls the ENERGY/QUALITY/POTENCY of the X-ray beam — higher kVp = more penetrating rays = lower contrast.
• Memory tool: Time & mA = Quantity | kVp = Quality/Energy
• Doubling exposure time doubles the number of photons but does NOT change their energy — this affects image density (darkness) but not contrast or penetrating ability.
• Exposure TIME: affects the QUANTITY (number) of X-rays/photons produced. Longer time = more electrons flow across the tube = more X-ray photons = denser/darker image.
• mA (milliamperage): also controls quantity — it determines the rate of electron flow (tube current).
• kVp (kilovoltage peak): controls the ENERGY/QUALITY/POTENCY of the X-ray beam — higher kVp = more penetrating rays = lower contrast.
• Memory tool: Time & mA = Quantity | kVp = Quality/Energy
• Doubling exposure time doubles the number of photons but does NOT change their energy — this affects image density (darkness) but not contrast or penetrating ability.