I looked it up and it gave me educational exercise, but I don't know if it is right.
Answer:
The percentage change in frequency is 10%.
Explanation:
Given that,
Amplitude decreases by 1/10 per second.
Resonance = 10 Hz
We need to calculate the change in frequency
Using formula of change in frequency

Put the value into the formula


We need to calculate the resonant frequency
Using formula of resonant frequency

Put the value into the formula


We need to calculate the percentage change in frequency
Using formula of percentage change in frequency


Hence, The percentage change in frequency is 10%.
Answer:
The allowed current in the cable is 1.15 A.
Explanation:
Given that,
Distance = 1.00 m
Suppose the magnetic field is
and if the experiment is to be accurate to 1.0 %
We need to calculate the current
Using formula of magnetic field


Put the value into the formula


If the experiment is to be accurate to 1.0%
Then,
We need to calculate the allowed current in the cable



Hence, The allowed current in the cable is 1.15 A.
Answer:
The right option is (d) substance undergoing a change of state
Explanation:
Latent Heat: Latent heat is the heat required to change the state of a substance without change in temperature. Latent heat is also known as hidden heat because the heat is not visible. The unit is Joules (J).
Latent heat is divided into two:
⇒ Latent Heat of fusion
⇒ Latent Heat of vaporization.
Latent Heat of fusion: This is the heat energy required to convert a substance from its solid form to its liquid form without change in temperature. E.g (Ice) When ice is heated, its temperature rise steadily until a certain temperature is reached when the solid begins to melts.
Latent Heat of vaporization: This is the heat required to change a liquid substance to vapor without a change in temperature. The latent heat depend on the mass of the liquid and the nature of the liquid. E.g When water is heated from a known temperature its boiling point (100°C) When more heat is supplied to its boiling temperature, it continue to boil without a change in temperature.
From The above, Latent heat brings about a change of state of a substance at a steady temperature.
The right option is (d) substance undergoing a change of state