Answer:
3.7 A
Explanation:
Parameters given:
Magnetic field strength, B = 5 * 10^(-5) T
Distance of magnetic field from wire, r = 1.5 cm = 0.015 m
The magnetic field, B, due to a current, I, flowing a wire is given as:
B = (μ₀*I) / 2πr
Where μ₀ = permeability of free space
To get the current, I, we make I the subject of the formula:
I = (2πr * B) / μ₀
I = (2 * 3.142 * 5 * 10^(-5)) / (1.25663706 × 10^(-6))
I = 3.7 A

- c. The weight of an object on the moon will be the same as its weight on Earth. It is false because the weight of an on the moon will be 1/6 th times its weight on Earth.
- d. The weight of an object is its mass multiplied by the force of gravity. The statement is false because the formula of weight is mass × acceleration due to gravity, not force of gravity.
- e. The mass and weight of an object are the same thing. The statement is false because mass means a body of matter. While weight of an object is its mass multiplied by the force of gravity.
- f. The mass of an object is the force of gravity acting upon an object. It is false because it will be the weight of the object not mass.
- So, the answers are c, d, e and f.
Hope you could understand.
If you have any query, feel free to ask.
A model train traveling at a constant speed around a circular track has a constant velocity. FALSE.
Hope this helps you!
Answer:
an electromagnet is a metal which has the ability to turn into a magnet on passing electricity through it .
But once the electric flow is withdrawn the circuit breaks and it no more behaves like a magnet.
but this is not so in permanent magnets
Explanation:
thus electromagnet is used in magnetic cranes bcoz their magnetism can be controlled conveniently.