Magnetic field direction is given by right hand thumb rule.
If we put our thumb in the direction of current then curl of fingers will show the magnetic field direction around the wire.
Now here since current is going into the screen so we will put our thumb into the screen and then the curl of fingers is clockwise around it.
The magnetic field is clockwise.
So this would be the direction of magnetic field
Answer:
The magnetic field through the wire must be changing
Explanation:
According to Faraday's law, the induced emf, ε in a metallic conductor is directly proportional to the rate of change of magnetic flux,Φ through it. This is stated mathematically as ε = dΦ/dt.
Now for the wire, the magnetic flux through it is given by Φ = ABcosθ where A = cross-sectional area of wire, B = magnetic field and θ = angle between A and B.
So, dΦ/dt = dABcosθ/dt
Since A and B are constant,
dΦ/dt = ABdcosθ/dt = -(dθ/dt)ABsinθ
Since dθ/dt implies a change in the angle between A and B, since A is constant, it implies that B must be rotating.
So, <u>for an electric current (or voltage) to be produced in the wire, the magnetic field must be rotating or changing</u>.
Answer:
1

2
The distance is
Explanation:
From the question we are told that
The maximum speed of the cheetah is 
The maximum of gazelle is 
The distance ahead is 
Let
denote the time which the cheetah catches the gazelle
Gnerally the equation representing the distance the cheetah needs to move in order to catch the gazelle is

=> 
=> 
=> 
Now at t = 7.5 s

=> 
=> 
=>
Hence the for the gazelle to escape the cheetah it must be 55.2 m
Answer:
B. +m
Explanation:
The magnification of an image is defined as the ratio between the size of the image and of the object:

where we have
y' = size of the image
y = size of the object
There are two possible situations:
- When m is positive, y' has same sign as y: this means that the image image is upright
- When m is negative, y' has opposite sign to y: this means that the image is upside down
Therefore, the correct option representing an upright image is
B. +m
False the North Star never changes it position