A milliammeter reads 10 mA full scale. It consists of a 0.20-$\Omega$ resistor in parallel with a 30-$\Omega$ galvanometer. How can you change this ammeter to a voltmeter giving a full-scale reading of $10 ~\mathrm{V}$ without taking the ammeter apart? What will be the sensitivity $(\Omega/\mathrm{V})$ of your voltmeter?

An ammeter has a sensitivity of 10,000 $\Omega/\mathrm{V}$. What current passing through the galvanometer produces full-scale deflection?

What is the resistance of a voltmeter on the 250-V scale if the meter sensitivity is 30,000 $\Omega/\mathrm{V}?$

How much work does the electric field do in moving a proton from a point with a potential of +125 V to a point where it is -55 V? Express your answer both in joules and electron volts.

The RC circuit of earlier Fig. has R = 6.7 k$\Omega$ and C = 3.0 $\mu$F. The capacitor is at voltage $V_o$ at t = 0, when the switch is closed. How long does it take the capacitor to discharge to $1.0$ percent of its initial voltage?

In earlier figure, the total resistance is 15 k$\Omega$ and the battery's emf is 24.0 V. If the time constant is measured to be 35 $\mu$s, calculate (a) the total capacitance of the circuit and (b) the time it takes for the voltage across the resistor to reach $16.0 ~\mathrm{V}$.

Suppose a 7.5-$\mu$F capacitor replaced the 10.0-$\Omega$ resistor in earlier Figure. Calculate: (a) the charge on the capacitor in the steady state-that is, after the capacitor reaches its maximum charge; (b) the steady state current through the other resistors.

Describe carefully the difference between emf and potential difference.

Suppose that you have a 6.0-V battery and you wish to apply a voltage of only 4.0 V. Given an unlimited supply of $1.0$-$\Omega$ resistors, how could you connect them so as to make a "voltage divider" that produced a $4.0$-$\mathrm{V}$ output for a $6.0$-$\mathrm{V}$ input?

A 7.0-$\mu$F and a 3.0-$\mu$F capacitor are connected in series and this combination is connected in parallel with a 4.0-$\mu$F capacitor. (a) What is the net capacitance?

(b) If 24 V is applied across the whole network, calculate the voltage across each capacitor.

A 200-pF capacitor is connected in series with an unknown capacitor, and as a series combination they are connected to a battery with an emf of 25.0 V. If the $200$-p$\mathrm{F}$ capacitor stores $125$ p$\mathrm{C}$ of charge on its plates, what is the unknown capacitance?

A 0.40-$\mu$F and a 0.50-$\mu$F capacitor are connected in series to a 9.0-V battery. Calculate (a) the potential difference across each capacitor, and (b) the charge on each. (c) Repeat parts (a) and (b) assuming the two capacitors are in parallel.

A circuit contains a single 150-pF capacitor hooked across a battery. It is desired to store three times as much energy in a combination of two capacitors by adding a single capacitor to this one. How would you hook it up and what would its value be?

You have three capacitors, of capacitance 2000 pF, 7500 pF, and 0.0100 $\mu$F. What is the maximum and minimum capacitance that you can form from these? How do you make the connection in each case?