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].
Velocity is about direction traveled in comparison to speed which is just distance with out direction
<span>If a mouse and an elephant both run with the same kinetic energy, can you say ... 3. if a car traveling at60 km/h will skid 20 m when its brakes lock, how far will it skid if it is traveling at 120 km/h when its brakes lock? (This question is typical on ...</span><span>just get this and figure it out and this is your answer </span>
Here is your answer

REASON :
We know that
Potential difference, V= W/q
where, W is work done
and, q is magnitude of charge
Given,
V= 9.0 v and W= 45 J
So,
using above relation, we get
9= 45/q
q= 45/9
q= 5 coulomb
HOPE IT IS USEFUL