A loop antenna of area A = 3.25 cm2 and resistance R = 7.17 μΩ is perpendicular to a uniform magnetic field of magnitude 20.2 μT. The field magnitude drops to zero in 2.03 ms. How much thermal energy is produced in joules in the loop by the change in field?

Explanation:

change in flux = area x change in magnetic field

= 3.25 x 10⁻⁴  x ( 20.2 - 0 ) x 10⁻⁶

= 65.65 x 10⁻¹⁰ Weber .

emf induced = change in flux / time

= 65.65 x 10⁻¹⁰ / 2.03 x 10⁻³

= 32.34 x 10⁻⁷ V

current = volt induced / resistance

= 32.34 x 10⁻⁷ / 7.17 x 10⁻⁶

= .451 A

Thermal energy produced = I²R t , I is current , R is resistance , t is time

= .451² x 7.17 x 10⁻⁶ x 2 .03 x 10⁻³

= 2.96 x 10⁻⁹ J .

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.