Answer:
A)
B)
C)
Explanation:
Given that:
- no. of turns i the coil,

- area of the coil,

- time interval of rotation,

- intensity of magnetic field,

(A)
Initially the coil area is perpendicular to the magnetic field.
So, magnetic flux is given as:
..................................(1)
is the angle between the area vector and the magnetic field lines. Area vector is always perpendicular to the area given. In this case area vector is parallel to the magnetic field.


(B)
In this case the plane area is parallel to the magnetic field i.e. the area vector is perpendicular to the magnetic field.
∴ 
From eq. (1)


(C)
According to the Faraday's Law we have:



Answer:
Final temperature, 
Explanation:
Given that,
Mass of silver ring, m = 4 g
Initial temperature, 
Heat released, Q = -18 J (as heat is released)
Specific heat capacity of silver, 
To find,
Final temperature
Solution,
The expression for the specific heat is given by :





So, the final temperature of silver is 21.85 degrees Celsius.
The average speed would be 33.29m/s.The average speed equation is:

First you will need to solve for the distance you traveled in each scenario. So we can solve this by getting the product of speed and the time traveled.
Scenario 1:
Speed = 29m/s
Time = 120s
Distance = ?
Distance = (29m/s)(120s)
= 3,480m
Scenario 2
Speed = 35m/s
Time = 300s
Distance = ?
Distance = (35m/s)(300s)
= 10,500m
Now that you have the distance of both, you can solve for your average speed.
Answer:
Compasses are mainly used in navigation to find direction on the earth. This works because the Earth itself has a magnetic field which is similar to that of a bar magnet. The compass needle aligns with the Earth's magnetic field direction and points north-south. Also, In a magnet all the domains are oriented in the same direction. In the case of a nail, the domains can be aligned in the same direction causing the nail to become magnetic. That is because if you hang a bar magnet from a thread, the north pole will point to magnetic north. When you bring one north pole close to another north pole they repel each other. You can feel the two magnets pushing each other apart.