Answer:

Explanation:
Electric field strength= Force/unit charge
E= (kQq/r²)/q ₓ r
where r is the unit vector in the direction of unit charge
E= 
The force required to start an object sliding across a uniform horizontal surface is larger than the force required to keep the object sliding at a constant velocity once it starts.
The magnitudes of the required forces are different in these situations because the force of kinetic friction is less than the force of static friction. <em>(d)</em>
<h3>Answer;</h3>
<u>It would make the lens stronger. </u>
<h3>Explanation;</h3>
- The focal length is the distance between the optical center or the center of the lens to the focal point of a convex or concave lens.
- The power of the convex lens is lens ability to undertake refraction or bend light. It is given as the reciprocal of focal length.
- Power of the lens = 1/ f; therefore the smaller the focal length the higher the power and the larger the focal length the lower the power.
- Thus; decreasing the focal length of a convex lens makes the lens stronger.
<em><u>One</u></em>
Givens
- delta B = 0.20 T/s
- A = 0.07 m^2
- R = 3.5 ohms
Formula
Φ = ΔB*A
e = Φ
Solution (first part)
e = 0.2 * 0.07
e = 0.014 emf
Solution (second part)
i = e/R
i = 0.014 / 3.5
i = 4 * 10^-3
i = 4 ma
Answer
A
<em><u>Two</u></em>
Givens
N = 200 turns
Φ = 30 degrees
Delta B = 0.45 T/s
phi = 30 degrees
r = 0.06 meters
Formula
e = -N * delta B * A * Cos(phi)
Solution
e = -200 * 0.45 (pi r^2) * Cos(30)
e = - 200 * 0.45 * (3.14 * 0.06^2) * cos(30)
e = 0.881 emf
Answer
A
In a direct current (DC) electrical circuit, the voltage (V in volts) is an expression of the available energy per unit charge which drives the electric current (I in amperes) around a closed circuit. Increasing the resistance (R in ohms) will proportionately decrease the current which may be driven through the circuit by the voltage.
Each quantity and each operational relationship in a battery-operated DC circuit has a direct analog in the water circuit. The nature of the analogies can help develop an understanding of the quantities in basic electric ciruits. In the water circuit, the pressure P drives the water around the closed loop of pipe at a certain volume flow rate F. If the resistance to flow R is increased, then the volume flow rate decreases proportionately. You may click any component or any relationship to explore the the details of the analogy with a DC electric circuit.