I’m almost 100 percent sure it’s the first one
Answer:
Explanation:
1 ) Magnetic field due to a circular coil carrying current
= μ₀I / 2r
I is current , r is radius of the wire , μ₀ = 4π x 10⁻⁷
= 4π x 10⁻⁷ x 15 / (2 x 3.5 x 10⁻²)
= 26.9 x 10⁻⁵ T
2 )
Negative z direction .
The direction of magnetic field due to a circular coil having current is known
with the help of screw rule or right hand thumb rule.
3 )
If we decrease the radius the magnetic field will:__increase _____.
A. Increase.
Magnetic field due to a circular coil carrying current
B = μ₀I / 2 r
Here r is radius of the coil . If radius decreases magnetic field increases.
So magnetic field will increase.
Answer:
f = 23.64 Hz
Explanation:
From the wave equation, the relationship between frequency and wavelength is given by;
f = cλ
Where;
λ is wavelength
c is speed of light with a constant value of 3 × 10^(8) m/s
f is frequency
We are given wavelength of 7.88 x 10^(-8) m
Thus;
f = 7.88 x 10^(-8) × 3 × 10^(8)
f = 23.64 Hz
Answer:
500 kW
Explanation:
Given that,
Energy of the train, E = 2 MJ = 2×10⁶ J
Time, t = 4 seconds
We need to find the power of the train. We know that,
Power = energy/time
So,

So, the power of the train is equal to 500 kW.