A thin, 46.0cm long metal bar with mass 800g rests on, but is not attached to, t

Question

A thin, 46.0cm long metal bar with mass 800g rests on, but is not attached to, two metallic supports in a uniform magnetic field with a magnitude of 0.400T , as shown in the figure. A battery and a resistor of resistance 25.0? are connected in series to the supports.

What is the largest voltage the battery can have without breaking the circuit at the supports?

The battery voltage has the maximum value calculated in part (a). If the resistor suddenly gets partially short-circuited, decreasing its resistance to 2.30? , find the initial acceleration of the bar.

A thin, 46.0cm long metal bar with mass 800g rests on, but is not attached to, two metallic supports in a uniform magnetic field with a magnitude of 0.400T , as shown in the figure. A battery and a resistor of resistance 25.0? are connected in series to the supports. What is the largest voltage the battery can have without breaking the circuit at the supports? The battery voltage has the maximum value calculated in part (a). If the resistor suddenly gets partially short-circuited, decreasing its resistance to 2.30? , find the initial acceleration of the bar.

Explanation / Answer

a)

F=BIL=ma

I=ma/BL =0.8*9.8/0.4*0.46

I=42.6 A

Since Current

I=V/R

=>V=I*R =42.6*25

V=1065.2 Volts

b)

I=V/R2=1065.2/2.3=463.13 A

Magnetic force

F=BIL=0.4*463.13*0.46=85.22 N

Force due to gravity

Fg=mg=0.8*9.8=7.84 N

acceleration

a=(F-Fg)/m =(85.22-7.84)/0.8

a=96.7 m/s2

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.