Correct Answer: A. coupling device

Explanation

Fiber optic couplers are used to split the input signals into two or more outputs, they are called splitters in this case.

On the other hand, some types of couplers can be used to combine two or more inputs into one single output, they are called combiners in this case.

Correct Answer: B. Diffusion

Correct Answer: A) 1.22 x 10-11m

Correct Answer: C. 1.50

Correct Answer: A. 125m

Explanation

speed = \(\frac{90 \times 10^3}{3600}\) = 25ms-1

Acceleration = velocity change / time = 25 / 10

: Acceleration = 2.5

Using S = Ut + \(\frac{1}{2}\) at^2

S = \(\frac{1}{2}\) X 2.5 X 10^2 = 125m

Correct Answer: A. Classical mechanics

Explanation

Classical mechanics is a branch of physics that deals with the motion of macroscopic objects. It is based on the principles of Newton's laws of motion and is not considered to be part of elementary modern physics.

The other three options, quantum mechanics, special relativity, and nuclear physics, are all considered to be part of elementary modern physics because they deal with the behavior of matter and energy at the atomic and subatomic levels.

Correct Answer: B. 10.0kgms^-1

Explanation

I = Ft = m(v - u) = 5 x 2 = 10kgms^-1

Correct Answer: C. 2.50 rad s^-1

Explanation

(a)(i) Coulomb's law of electrostatics

The electrostatic force between two charged bodies is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

(ii) Calculation of the magnitude of the electrostatic force

F = \(\frac{kq_{1}q_{2}}{d^{2}}\)

F = \(\frac{9.0 \times 10^{9} \times 1.6 \times 10^{-19} \times 1.6 \times 10^{-19}}{(5.2 \times 10^{-11})^{2}}\)

= 8.52 x 10\(^{-8}\) N

(b)(I) Proof of V\(_{out}\)

Let the current through the circuit be I

V\(_{in}\) = I(R\(_{1}\) + R\(_{2}\))

OR

I = \(\frac{V_{in}}{R_{1} + R_{2}}\)

V\(_{out}\) =IR\(_{2}\)

II. Calculation of R\(_{1}\);

V\(_{out}\) = V\(_{in}\)(\(\frac{R_{1}}{R_{1} + R_{2}}\))

OR

\(\frac{V_{out}}{V_{in}} = \frac{R_{1}}{R_{1} + R_{2}}\)

\(\frac{1}{2.5} = \frac{R_{1}}{R_{1} + R_{30}}\)

R\(_{1}\) = 20\(\Omega\)

(ii) The Volt The unit of potential difference between two points when one joule of work is done in taking one coulomb of charge between the points,

(c) Why wood is not suitable for use as the Core of transformers Wood is a non-magnetic material and would not provide magnetic coupling between the coils for electromagnetic induction.

(d) Applications of cathode ray tube

i. For studying alternating current waveform

ii. For measuring frequency/voltage/ reactance/power factor and resistance of an electronic device

iii. Used to monitor signals/check FM/AM characteristics

Correct Answer: D) optical pyrometer