Answer:
Explanation:
The wires are in circular shape . They have common center .
magnetic field due to circular wire is given by the formula
B =
where I is current , r is radius of the coil .
magnetic field due to inner wire
=
magnetic field due to outer wire
=
These should be equal and opposite so that by cancelling each other , they create zero field.
=
I = 16.66 A
Direction of current should be in opposite direction ie anticlockwise when looking from above.
Answer:
9R
Explanation:
We know that the resistance is .
If we stretch the wire to a new length L2 = 3L, the cross-sectional area will also change. If the cross-sectional area doesn't change throughout the wire, we can say that:
Volume = L*A = 3L * A2 being A2 the new area after stretching the wire.
Since the volume remains the same we conclude that A2 = A/3
With this information, we calculate the new resistance:
Since , and by simple inspection of the previous equation, we get:
<em>R2 = 9*R</em>
Ryan applied a force of 10N and moved a book 30 cm in the direction of the force. How much was the work done by Ryan?
<h2><u>Answer:</u><u>-</u></h2><h3>Given,</h3>=> Force applied by Ryan = 10N
=> Distance covered by the book after applying force = 30 cm
<h3>And,</h3>30 cm = 0.3 m (distance)
<h3>So,</h3>=> Work done = Force × Distance
=> 10 × 0.3
=> 3 Joules