Answer:
Explanation:
We are given that
Current in wire=40 A
Magnetic field=
T( vertically downward)
We have to find the resultant magnitude of the magnetic field 29 cm above the wire and 29 cm below the wire.
According to Bio-Savart law, the magnetic field exerted by the wire at distance R is given by
We have R=29 cm=
1 m=100 cm
Substitute the values in the given formula
The resultant magnetic field is given by
Substitute the values then we get
The resultant magnitude of magnetic field is same above and below the wire as it is at same distance.
The resultant magnitude of the magnetic field 29 cm below the wire=
Hence, the resultant magnitude of the magnetic field 29 cm above the wire=
Answer:
d. All of these
Explanation:
work is said to be done when a force is applied to an object through a certain distance. the SI unit of workdone is joules or newton per meter
mathematically
workdone = force x distance.
from the answers, work is being done because there is force applied in a certain distance.
- from wagon is used to carry vegetables from a garden.
- pulley is used to get water from a well.
- hammer is used to remove a nail from a wall.
What’s the answer choices to pick from?
Answer:
a) P=0.25x10^-7
b) R=B*N2*E
c) N=1.33x10^9 photons
Explanation:
a) the spontaneous emission rate is equal to:
1/tsp=1/3 ms
the stimulated emission rate is equal to:
pst=(N*C*o(v))/V
where
o(v)=((λ^2*A)/(8*π*u^2))g(v)
g(v)=2/(π*deltav)
o(v)=(λ^2)/(4*π*tp*deltav)
Replacing values:
o(v)=0.7^2/(4*π*3*50)=8.3x10^-19 cm^2
the probability is equal to:
P=(1000*3x10^10*8.3x10^-19)/(100)=0.25x10^-7
b) the rate of decay is equal to:
R=B*N2*E, where B is the Einstein´s coefficient and E is the energy system
c) the number of photons is equal to:
N=(1/tsp)*(V/C*o)
Replacing:
N=100/(3*3x10^10*8.3x10^-19)
N=1.33x10^9 photons
