Answer:
b.
Explanation:
In case of Single Slit, diffraction will occur.
Then In Single slit Diffraction, width of central fringe is

where D= distance b/w screen and slit
a= slit width
\lambda = wavelength
Thus if Screen width increases keeping other factors same then width of central fringe becomes narrower as

On increasing the slit width the central bright fringe width The width of the central bright fringe becomes narrower.
Answer:
Yes, It is true.
The acceleration due to gravity is caused by field force.
Answer:
346.66 Hz
Explanation:
= Length of string which is unfingered = l
= Length of string which is vibrate when fingered = 
= Unfingered frequency = 260 Hz
= Fingered frequency
Frequency is inversely proportional to length

So,

The frequency of the fingered string is 346.66 Hz
The basic principles that apply to circuits is that electrons must receive energy from a source, and electrons transfer energy to perform some useful function.
<h3 /><h3>What is circuit?</h3>
Individual electronic components, like resistors, transistors, are connected by metallic wires or traces by which the electric current can flow to form a circuit design.
The basic principles that apply to circuits will be;
1. Electrons must receive energy from a source.
2. Electrons transfer energy to perform some useful function.
Hence, option 1 and 2 are correct.
To learn more about the circuit, refer to the link;
brainly.com/question/21505732
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