Wavelength is the distance between 2 adjacent points in a wave
we can use the following equation to find the wavelength of a sound wave
wavelength = speed / frequency
frequency is the number of waves passing a point in 1 second
substituting the values in the equation
wavelength = 343 m/s / 686 Hz
wavelength = 0.5 m
wavelength of the wave is 0.5 m
Answer:
1) current = I
2) Resistance = V/I
3) current = 2I
4) resistance = V/2I
5) current = 3I
6) Resistance = V/3I
7) Current = 4I
8) Resistance = V/4I
Explanation:
When one bulb is connected across the battery then let say the current is given as I
Then resistance is given as

When two bulbs are in parallel with the battery then
total current becomes twice of initial current
so we have
current = 2I
Resistance of the circuit is now

When three bulbs are in parallel with the battery then
total current becomes three times of initial current
so we have
current = 3I
Resistance of the circuit is now

When four bulbs are in parallel with the battery then
total current becomes four times of initial current
so we have
current = 4I
Resistance of the circuit is now

Electricians are advised to wear rubber gloves to protect themselves from being shocked.