Consider two identical electric bulbs of power P and resistance R. You connect them to a battery of voltage V. The first time you connect them in series with each other, and the second time in parallel. How will the illumination of the connection in parallel compare with the connection in series?

a. 1/2 of the illumination of connection in series

b. 2X as much illumination as connection in series

c. 1/4 of the illumination of connection in series

d. The same illumination as connection in series

e. 4X greater illumination as connection in series

E

Explanation:

When the two identical electric bulbs of power P and resistance are connected in series;

P = IV = V ( V/R) = V² / R

and V = IR

for series connection, the effective resistance Rf = R + R = 2R

and current in the circuit I₁ = V / 2R

for the parallel connection ,

= +

Rf = R / 2

I₂, in the circuit = 2 V / R

comparing the current,

I₂ ÷ I₁ = 2 V / R ÷ V / 2R = 4 : 1

The illumination is 4 times as greater in connection in series

does anyone know or what?

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s