Answer:
Explanation:
Given that,
B(t) = B0 cos(ωt) • k
Radius r = a
Inner radius r' = a/2 and resistance R.
Current in the loop as a function of time I(t) =?
Magnetic flux is given as
Φ = BA
And the Area is given as
A = πr², where r = a/2
A = πa²/4
Then,
Φ = ¼ Bπa²
Φ(t) = ¼πa²Bo•Cos(ωt)
Then, the EMF is given as
ε(t) = -dΦ/dt
ε(t) = -¼πa²Bo • -ωSin(ωt)
ε(t) = ¼ωπa²Bo•Sin(ωt)
From ohms law,
ε = iR
Then, i = ε/R
I(t) = ¼ωπa²Bo•Sin(ωt) /R
This is the current induced in the loop.
Check attachment for better understanding
(A) We can solve the problem by using Ohm's law, which states:

where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know

and

, therefore we can rearrange Ohm's law to find the current through the device:

(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:

where

is the resistivity of the material of the wire
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.
Answer: The box was moving with a velocity of 0.256m/s when it hit the spring
Explanation: Please see the attachments below
Answer:
v = 10 m/s
Explanation:
given,
Mass of Mercedes engine = 2000 Kg
Power delivered = 100 kW
angle made with horizontal = 30°
acceleration due to gravity = 10 m/s²
largest speed car can sustain = ?
we know,
Power = Force x velocity
P = F x v
P = mg sinθ x v
P = mg sin 30° x v
P = 0.5 mg x v

v = 10 m/s
hence, the maximum velocity is equal to v = 10 m/s
Answer: D
Explanation:
A -amount of work
F-force
s-distance
If you keep same Force(F) and increase distance(s), amount of work will increase, according to:
A=F*s