Answer:
Explanation:
Given that,
Radius r = 15cm = 0.15m
Area of the circular loop can be determined using the formula for area of a circle
A = π r²
A = π × 0.15²
A = 0.0708 m²
Magnetic field B = 1.2T in positive z direction
B = 1.2 •k T.
If loop is remove from the field in the time interval
∆t = 2.3ms = 2.3×10^-3s
We want to find the average EMF and it is given as
ε = —∆Φ/∆t
The final flux is zero
Φf = 0
Where magnetic flux is given as
Φi = BA Cosθ
Where θ=0 since the area and the magnetic field point in the same direction.
Φi = BA Cos0
Φi = BA
Φi = 1.2 × 0.0708
Φi = 0.0848 Vs
Then, ε = —∆Φ/∆t
ε = —(Φf — Φi) / ∆t
ε = —(0-0.0848) / (2.3×10^-3)
ε = 0.0848 / (2.3×10^-3)
ε = 36.88 V
The EMF is 36.88 Volts
Answer:
At a distance of 1376.49 candle emits 0.2 watt power
Explanation:
Distance between Sun and earth 
Sun emits a power of 
Power emitted by candle = 0.20 watt
We know that brightness is given by
So 
So at a distance of 1376.49 candle emits 0.2 watt power
Answer: d)
Explanation: In order to justify the answer we have to consider that the energy of photons directely depent on the frequency so the energy is inverselly dependent of the wavelegth.
If both beams have the same power, this means Energy/time so the number of photons per second must be different. As consequence a) is wrong as b) since it is not posible since UV photon have more energy that IR photons. c) It is no necessary know the frequency since the wavelength is related in the form:
c=λν c is the speed of light, λ the wavelegth and ν the frequency.
d) Certainly will be more more IR photons than UV photons to get the same beam power.
Answer: Moon is much smaller in size and has very less mass, when compared to our mighty earth and there is absence of strong magnetic field on the moon which could protect from the incoming solar radiation from the sun. Since there is no magnetic field, it can swipe off any materials that are present there on the moon, diminishing the atmosphere.
This is the reason why moon does not have any atmosphere.
