A man pushes a lawn mower on a level lawn with a force of 250N. If 40% of this force is directed downward, how much work is done
1 answer:
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Answer:
(a) 108
(b) 110.500 kW
(c) 920.84 A
Solution:
As per the question:
Voltage at primary, (rms voltage)
Voltage at secondary, (rms voltage)
Current in the secondary,
Now,
(a) The ratio of secondary to primary turns is given by the relation:
where
= No. of turns in primary
= No. of turns in secondary
≈ 108
(b) The power supplied to the line is given by:
Power, P =
(c) The current rating that the fuse should have is given by:
Answer:
(a) False
(b) True
(c) True
(d) True
(e) True
(f) True
Explanation:
(a) Maxwell's equations not only applies to constant fields but it applies to both the fields, i.e., Time variant field as well as Time Invariant field.
(b) We make use of the Modified form of the Ampere's law and Faraday's Law to derive the wave equation.
(c) Electromagnetic waves contains both the electric and magnetic fields and these fields oscillates at an angle of to the direction of wave propagation.
(d) In free space both the electric and magnetic fields are in phase while considering electromagnetic waves.
(e) In free space or vacuum, the expression for the speed of light in terms of electric and magnetic field is given as:
Thus the ratio of the magnitudes of the electric and magnetic field vectors are equal to the speed of light in free space.
(f) In free space or in vacuum the energy density of the electromagnetic wave is divided equally in both the fields and hence are equal.
Answer:
The equivalent resistance of the combination is 3.42 ohms.
Explanation:
We have,
8 ohms resistor is connected in parallel with a 6 ohms resistor. It is required to find the equivalent resistance of this combination.
For a parallel combination, the equivalent resistance is given by :
Plugging the values of R₁ and R₂, we get :
So, the equivalent resistance of the combination is 3.42 ohms.