In a string of length L, the wavelength of the n-th harmonic of the standing wave produced in the string is given by:

The length of the string in this problem is L=3.5 m, therefore the wavelength of the 1st harmonic of the standing wave is:

The wavelength of the 2nd harmonic is:

The wavelength of the 4th harmonic is:

It is not possible to find any integer n such that
, therefore the correct options are A, B and D.
Answer: Stars are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of stars provides enough energy to make them shine brightly for many years. The exact lifetime of a star depends very much on its size.
Explanation: I try to do your question, hope this help
In a circuit having 2 lamps are connected in parallel to a battery
then the two lamps will be having the same potential as the battery
i.e

As per Ohm's law,
and 
In other words, each lamp's current is inversely related to its individual resistance. We only know the current in one of the bulbs in this specific instance. We would therefore need further information in order to calculate the current in the other light. Therefore, there isn't enough data to make a statement.
Under the assumption that all physical parameters, including temperature, remain constant, Ohm's law asserts that "the voltage across a conductor is directly proportional to the current flowing through it".
Learn more about Ohm's law here
brainly.com/question/2264542
#SPJ4
1333.3 is the frequency in the hertz of a signal that repeats 80,000 times within one minute. 0.00075 is its period.
The frequency of a repeated event is its number of instances per unit of time. In some cases, it is also referred to as temporal frequency or ordinary frequency to underline differences with spatial and angular frequencies, respectively.
The length of time it takes for a particle in a medium to complete one full vibrational cycle is the period of a wave. Being a time, a period is measured in time units like seconds, hours, days, or years. The Earth's orbit around the Sun has a duration of around 365 days, and one cycle of the Earth lasts 365 days.
frequency = cycle /second
frequency = 80000 / 60
frequency = 1333.3 hertz
Period = 1 / frequency
Period = 1 / 1,333.3
Period = 0.00075
To know more about frequency refer to: brainly.com/question/14472937
#SPJ4
Answer:
I believe true im very sorry if I'm wrong.