Answer:
Right hand thumb rule : It is a rule used to find the magnetic field direction around current carrying wire .
Explanation:
It states that : "If you grasp conductor in your right hand such that thumb points in upward direction ,then the direction in which our finger curls gives the direction of magnetic field or magnetic lines of forces" .
This rule proves that :Current can give rise to magnetism .
Around every current carrying conductor there exist a magnetic field which can be easily felt .
According to this rule : When a current flows in upward direction ,the finger curls in anticlockwise direction and when direction of current reverses ,then the direction of field also reverses .
Answer:
A. 10 joules
Explanation:
Given parameters:
Mass of object = 4kg
Speed = 5m/s
Unknown:
Kinetic energy of the the object = ?
Solution:
Kinetic energy is the energy due to a moving body.
So;
mathematically;
K.E = x m v²
m is the mass
v is the velocity
K.E = x 4 x 5 = 10J
The amount of work done by two boys who apply 200 N of force in an unsuccessful attempt to move a stalled car is 0.
Answer: Option B
<u>Explanation: </u>
Work done is the measure of work done by someone to push an object from its present position. We can also define work done as the amount of forces needed to move an object from its present position to another position. So the amount of work done is directly proportionate to the product of forces acting on the object and the displacement of the object.
So in this present case, as the two boys have done an unsuccessful attempts to push a stalled car so that means the displacement of the car is zero as there is no change in the position of the car. But they have applied a force of 200 N each. So the amount of work done will be
Thus, the amount of work done by two boys will be zero due to their unsuccessful attempt to move a stalled car.