2019 - JAMB Physics Past Questions and Answers - page 2

J.J Thompson discovered electron in 1879

Rutherford's model assumed the following which forms limitations of the model:

• energy is radiated when electrons are revolving
• energy is radiated in a continuous mode

Reactance is a form of opposition that electronic components exhibit to the passage of alternating current (alternating current) because of capacitance or inductance.

Resistance and reactance combine to form impedance

The fluctuation of d.c signal results from the rectification of AC to DC

In general, surface tension decreases when the temperature increases because cohesive forces decrease with an increase of molecular thermal activity. The influence of the surrounding environment is due to the adhesive action of liquid molecules that they have at the interface.

Formula:

u + v = 40

\(\frac{v}{u}\) = 3

v = 3u

u + 3u = 40

4u = 40

u = 10cm

v = 3u = 30cm

f = \(\frac{uv}{u + v} = \frac{10(30)}{10 + 30} = \frac{300}{40}\)

f = 7.5 cm

When a ray of light passes through the centre of curvature, it is returned along the same path with the angle difference along the same path equal to zero

Increased brightness leads to a less sharp or blurred image. Also, increase brightness is consequent upon a large hole or multiple pinholes

F = BIL

F = 0.4 x 6 x \(\frac{15}{100}\)

F = 0.36N

P = 0.45cm,

L = 60cm,

Efficiency(eff) = 75/π%

Hence, M.A = 200