Answer:
A. China rose
B. Methyl red
C. Phenolphthalein
Explanation:
An indicator is a substance used to detect the presence of an acid or base as characterized by the indicators color change. An indicator can either be natural or synthetic depending on whether it is obtained from naturally occurring substance (natural) or synthesized in a laboratory (synthetic).
A. China rose is a type of natural indicator that turns deep PINK or MAGENTA in the presence of an acid or GREEN in the presence of a base.
B. Methyl red is a synthetic Indicator that turns RED in the presence of an acid or YELLOW in the presence of a base.
C. Phenolphthalein is an organic dye that is originally colorless but turns PINK in the presence of a base but remains colorless in the presence of an acid or neutral substance.
Answer:
The work function of the metal is 2.226 eV.
Explanation:
Given;
wavelength of the violet light, λ = 427 nm = 427 x 10⁻⁹ m
maximum kinetic energy, K.E = 0.684 eV
The energy of the incident light is calculated as;
Apply Einstein's photoelectric equation;
E = Ф + K.E
where;
Ф is the work function of the metal
Ф = E - K.E
Ф = 2.91 eV - 0.684 eV
Ф = 2.226 eV.
Therefore, the work function of the metal is 2.226 eV.
This doesnt make sense. 2g<span>Δym is simply an equation. </span>
Answer:
3.33 minutes (3 minutes and 20 seconds)
Explanation:
Speed of the runner = s = 5 m/s
We need to calculate how will it take for runner to complete 1 km. We have the speed, the distance and we need to find the time. Before performing any calculations, we must convert the values to same units.
Speed is in m/s and distance is in kilometers. So we have to either convert speed to km/s or distance into meters. In this case, converting distance into meters would be a convenient option.
1 kilo meters = 1000 meters
The distance, speed and time are related by the equation:
Distance = Speed x Time
So,
Time = Distance/Speed
Using the values, we get:
t = 1000/5
t = 200 seconds
This means, the runner can complete 1 kilometers in 200 seconds. Since, there are 60 seconds in a minute, we can convert this time to minutes, by dividing it by 60. i.e.
Thus, it will take the runner 3.33 minutes (3 minutes and 20 seconds) to travel 1 km.
Correct answer choice is :
D) In a forward-biased setup, large numbers of charge carriers will be pulled across the junction and result in a large current.
Explanation:
P-n junction diode is the easiest mode of all the semiconductor tools. Despite, diodes act a significant role in many electronic appliances. A p-n junction diode can be utilized to change the alternating current to the direct current. These diodes are applied in power supply accessories. Battery attached across the p-n junction causes the diode forward biased, pushing particles from the n-type to the p-type and starting holes in a different way. Electrons and holes cross the junction and join. Photons are carried off as the electrons and holes recombine.
