458
PROBLEMS
.
14—2. Express equation 14—17 in Mev and also in milli-ergs.
_
14—3. Write the equations for the reactions described in the rst
paragraph of section 14—19.
_
17—1'. The voltage sensitivity of an electroscope is 200 divisions per
volt.
Its capacity is 2 e.s.u. A certain current moves the leaf «at the
rate of 0.1 divisions per second.
What is the value of this current in
amperes?
(1.11 X 10“15 amp.s)
17—2. The leaf of an electroscope is found to pass over 10 divisions in
10 seconds when a radioactive substance is nearby. A standard condenser is placed in parallel With the instrument. The leaf then takes 50
seconds to pass over the same number of divisions.
The standard condenser is made of two concentric cylinders of length 10 cm. The outside diameter of the inner cylinder is 2 cm. and the inside diameter of
the outer one is 3 cm.
What is the capacity of the electroscope?
,
(3.08 e.s.u.)
17—3. The voltage sensitivity of a quadrant electrometer is 1,000 scale
divisions per volt.
capacity is 50 e.s.u. A certain current causes a
motion of 0.1 divisions per second.
What is the value of this current in
amperes?
,
(5.56 X 10“15 camps)
17—4. The voltage sensitivity of a quadrant electrometer is 600 divisions per volt and its capacity is 100 e.s.u. _What charge, in coulombs,
must
be added to the system in order to produce a deflection of 20
divisions?
,
’
17—5. An ionization chamber alone has a capacity of (C' = ) 20 e.s.u.
With lead wires and electrometer, the capacity is 70 e.s.u. What is the
effect on the output current of doubling the length of the ionizatiol}
"chamber.P
(i.e., C = 40 e.s.u.) -
,
,
In the generating voltmete‘r of gure 19—3, the capacita'nce
-betWeen 111 and B is two e.s.u. .If the current through the galvanometer
is found to'be three microamperes when the rotor
turning With a Speed
,
1800 r.p.rri., what is the voltage V?
_
,
'
'
,
'
19—2G1ven,2 condensers, of 1,u.f. and %,uf., in series. If-an electro—‘
_
“
*
stat1€voltmeteracross the larger one—[reads 400 volts, nd the‘total Voltage;
‘
…<
nd1thtthmu end
«…
,"
…
"
,
"
19—3Atubeof0necentimeter dlameter,Wh1ChW1lllaterbeusedasa
GelgefMuïlercountertubehasa 3 m(dlameter>wremounted along
txThvltgbtWthw dth tb 1200 vlt
PROBLEMS
.
14—2. Express equation 14—17 in Mev and also in milli-ergs.
_
14—3. Write the equations for the reactions described in the rst
paragraph of section 14—19.
_
17—1'. The voltage sensitivity of an electroscope is 200 divisions per
volt.
Its capacity is 2 e.s.u. A certain current moves the leaf «at the
rate of 0.1 divisions per second.
What is the value of this current in
amperes?
(1.11 X 10“15 amp.s)
17—2. The leaf of an electroscope is found to pass over 10 divisions in
10 seconds when a radioactive substance is nearby. A standard condenser is placed in parallel With the instrument. The leaf then takes 50
seconds to pass over the same number of divisions.
The standard condenser is made of two concentric cylinders of length 10 cm. The outside diameter of the inner cylinder is 2 cm. and the inside diameter of
the outer one is 3 cm.
What is the capacity of the electroscope?
,
(3.08 e.s.u.)
17—3. The voltage sensitivity of a quadrant electrometer is 1,000 scale
divisions per volt.
capacity is 50 e.s.u. A certain current causes a
motion of 0.1 divisions per second.
What is the value of this current in
amperes?
,
(5.56 X 10“15 camps)
17—4. The voltage sensitivity of a quadrant electrometer is 600 divisions per volt and its capacity is 100 e.s.u. _What charge, in coulombs,
must
be added to the system in order to produce a deflection of 20
divisions?
,
’
17—5. An ionization chamber alone has a capacity of (C' = ) 20 e.s.u.
With lead wires and electrometer, the capacity is 70 e.s.u. What is the
effect on the output current of doubling the length of the ionizatiol}
"chamber.P
(i.e., C = 40 e.s.u.) -
,
,
In the generating voltmete‘r of gure 19—3, the capacita'nce
-betWeen 111 and B is two e.s.u. .If the current through the galvanometer
is found to'be three microamperes when the rotor
turning With a Speed
,
1800 r.p.rri., what is the voltage V?
_
,
'
'
,
'
19—2G1ven,2 condensers, of 1,u.f. and %,uf., in series. If-an electro—‘
_
“
*
stat1€voltmeteracross the larger one—[reads 400 volts, nd the‘total Voltage;
‘
…<
nd1thtthmu end
«…
,"
…
"
,
"
19—3Atubeof0necentimeter dlameter,Wh1ChW1lllaterbeusedasa
GelgefMuïlercountertubehasa 3 m(dlameter>wremounted along
txThvltgbtWthw dth tb 1200 vlt