<span>Friction
can help us play tennis, knock down bowling pins, and cook dinner.</span>
1. All the relevant resistors are in series, so the total (or equivalent) resistance is the sum of the resistances of the resistors: 20 Ω + 80 Ω + 50 Ω = 150 Ω [choice A].
2. The ammeter will read the current flowing through this circuit. We can find the ammeter reading using Ohm's law in terms of the electromotive force provided by the battery: I = ℰ/R = (30 V)(150 Ω) = 0.20 A [choice C].
3. The voltmeter will measure the potential drop across the 50 Ω resistor, i.e., the voltage at that resistor. We know from question 2 that the current flowing through the resistor is 0.20 A. So, from Ohm's law, V = IR = (0.20 A)(50 Ω) = 10. V, which will be the voltmeter reading [choice F].
4. Trick question? If the circuit becomes open, then no current will flow. Moreover, even if the voltmeter were kept as element of the circuit, voltmeters generally have a very high resistance (an ideal voltmeter has infinite resistance), so the current moving through the circuit will be negligible if not nil. In any case, the ammeter reading would be 0 A [choice B].
Answer:
<em>Magnetic</em><em> </em><em>compass</em><em> </em><em>helps</em><em> </em><em>to </em><em>identify</em><em> </em><em>direction</em><em> </em><em>in </em><em>this </em><em>way </em><em>,</em><em> </em><em>this </em><em>compass</em><em> </em><em>work </em><em>because</em><em> </em><em>of </em><em>earth</em><em> </em><em>magnetic</em><em> field</em><em> </em><em>and </em><em>show</em><em> </em><em>us </em><em>direction</em><em> </em>
<em> </em><em> </em><em>hope</em><em> it</em><em> helps</em><em> and</em><em> your</em><em> day</em><em> will</em><em> be</em><em> full</em><em> of</em><em> happiness</em><em>. </em>^_^
<span>Porous material has many spaces that can hold(store) groundwater.</span>
