A p.d. of 12 V is connected between P and Q. What is the p.d. between X and Y?
4 V.
6 V.
0 V.
8 V.
A galvanometer has an internal resistance of 100 Ohms and deflects full-scale at 2.00 mA. What size resistor should be added to it to convert it to a milliammeter capable of reading up to 4.00 mA?
50.0 Ohms in parallel.
50.0 Ohms in series.
100 Ohms in series.
100 Ohms in parallel.
Electrons drift through a section of a piece of copper wire containing 1029 electrons per unit volume with a velocity of 2.9 × 10⁻⁴ m/s.
The current density through the wire is:
2.9 × 1025 A/m².
4.6 × 10⁶ A/m².
5.5 × 1013 A/m².
4.6 × 1013 A/m².
A galvanometer with a coil resistance of 40.0 W deflects full scale for a current of 2.0 mA. What series resistance should be used with this galvanometer in order to construct a voltmeter that deflects full scale for 50 V?
25 k Ohms.
31 k Ohms.
27 k Ohms.
29 k Ohms.
