Answer:
R2 = 10.31Ω
Explanation:
For two resistors in parallel you have that the equivalent resistance is:
(1)
R1 = 13 Ω
R2 = ?
The equivalent resistance of the circuit can also be calculated by using the Ohm's law:
(2)
V: emf source voltage = 23 V
I: current = 4 A
You calculate the Req by using the equation (2):

Now, you can calculate the unknown resistor R2 by using the equation (1):

hence, the resistance of the unknown resistor is 10.31Ω
Answer: A)
Explanation: when an electron is placed in a magnetic field, it experiences a force.
This force is given below as
F=qvB*sinθ
F = force experienced by charge.
q = magnitude of electronic charge
v = speed of electron
B= strength of magnetic field
θ = angle between magnetic field and velocity.
What defines the force exerted on the charge is the angle between the field and it velocity.
If magnetic field is parallel to velocity, then it means that θ=0° which means sin 0 = 0, which means
F = qvB * 0 = 0.
The charge being at rest has nothing to do with the angle between magnetic field strength and velocity.
The answer is C because <span>this movement is caused by the heat in Earth and creates </span>convection currents. <span>Convection currents in the asthenosphere cause movement of Earth's tectonic plates. </span>
The resultant vector can be determined by the component vectors. The component vectors are vector lying along the x and y-axes. The equation for the resultant vector, v is:
v = √(vx² + vy²)
v = √[(9.80)² + (-6.40)²]
v = √137 or 11.7 units