Answer:
D. 
Explanation:
The speed of sound in dry air is given approximately by
The vertical velocity is affected by the acceleration of gravity (ignoring the effects of air resistance usually)
Answer:
An element is made of only one type of atom. (Oxygen or sulphur) A compound is two or more elements that are chemically combined. (Iron oxide or Carbon monoxide)
Explanation:
<u>Out of all given choices, the following statements are true:</u>
- An ammeter is used to measure current.
- A voltmeter is used to measure voltage.
- A voltmeter must be placed in parallel with a resistor to measure the voltage across the resistor.
Options A, E, and F
<u>Explanation:</u>
An instrument by which the current in a circuit is measured is called ammeter whereas an instrument in which voltage is measured in a circuit is called a voltmeter . The ammeter is placed in series with the resistor while the voltmeter is placed in parallel with the resistor.
For the option B, since the ammeter must be placed in series with the resistor to measure current, it is false. Option C is false because an ammeter has zero internal resistance. Option D is also false because a voltmeter has a high internal resistance and is actually infinite.
