Light of wavelength 400 nm and a power of 1.83 x 10-6 w is incident onto a photodetector with quantum efficiency 0.57. the sensor is connected to a 5.7 k52 load resistor and operated at a temperature of 300 k. (a) determine the responsivity of the detector. (b) determine the photocurrent produced by the detector. (c) if the sensor is connected to a 5.7 ks2 load resistor, determine the voltage generated across the load resistor from this photocurrent. (d) if the detector is dominated by johnson noise and has a measurement bandwidth of 1 mhz, estimate the snr.

a and c

c is 100% but i am confused in a

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.

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