The electric flash attachment for a camera contains a capacitor for storing the energy used to produce the flash. In one such unit, the potential difference between the plates of 20 F capacitor is 5V. Calculate the energy that is used to produce the flash?
Correct answer: A. 250 J
- A. 250 J
- B. 310 J
- C. 500 J
- D. 650 J
Explanation
from the formula E= 1/2CV2 =1/2 x 20 x 52 =10 x 25 =250 J
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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