<< Chapter < Page Chapter >> Page >

Analog meters use a galvanometer, which essentially consists of a coil of wire with a small resistance and a pointer with a scale attached. When current runs through the coil, the point turns; the amount the pointer turns is proportional to the amount of current running through the coil. Galvanometers can be used to make a voltmeter if a resistor is placed in series with the galvanometer. Consider a galvanometer that has a resistance of 25.00 Ω and gives a full scale reading when a 50 - μ A current runs through it. The galvanometer is to be used to make an voltmeter that has a full scale reading of 10.00 V, as shown below. Recall that a voltmeter is connected in parallel with the component of interest, so the meter must have a high resistance or it will change the current running through the component. (a) What is the potential drop across the series resistor in the meter? (b) What is the resistance of the parallel resistor?

The figure shows a resistor R subscript S connected in series with a voltmeter with resistance R subscript M. The voltage difference across the ends is 10 V.

a. V s = V I M R M = 9.99875 V ; b. R S = V P I M = 199.975 k Ω

Got questions? Get instant answers now!

Consider the circuit shown below. Find I 1 , V 1 , I 2 , and V 3 .

The circuit shows positive terminal of voltage source V of 12 V connected to an ammeter connected to resistor R subscript 1 of 1 Ω with voltmeter across it connected to two parallel branches. The first branch has an ammeter connected to resistor R subscript 2 of 6 Ω and second branch has R subscript 3 of 13 Ω and voltmeter across it.
Got questions? Get instant answers now!

Consider the circuit below. (a) What is the RC time constant of the circuit? (b) What is the initial current in the circuit once the switch is closed? (c) How much time passes between the instant the switch is closed and the time the current has reached half of the initial current?

The circuit shows positive terminal of voltage source V subscript 1 of 24 V connected to negative terminal of voltage source of voltage source V subscript 2 of 24 V. The positive terminal of V subscript 2 is connected to an open switch. The other end of the switch is connected to capacitor C subscript 1 of 100 mF which is connected to two parallel branches, one with resistor R subscript 2 of 10 kΩ and other with R subscript 1 of 10 kΩ and R subscript 3 of 30 kΩ. The two branches are connected to source V subscript 1 through resistor R subscript 4 of 30 kΩ.

a. τ = 3800 s ; b. 1.26 A; c. t = 2633.96 s

Got questions? Get instant answers now!

Consider the circuit below. (a) What is the initial current through resistor R 2 when the switch is closed? (b) What is the current through resistor R 2 when the capacitor is fully charged, long after the switch is closed? (c) What happens if the switch is opened after it has been closed for some time? (d) If the switch has been closed for a time period long enough for the capacitor to become fully charged, and then the switch is opened, how long before the current through resistor R 1 reaches half of its initial value?

The positive terminal of voltage source V subscript 1 of 24 V is connected to an open switch. The other end of the switch is connected to two parallel branches, one with resistor R subscript 1 of 10 kΩ and other with capacitor C of 10 μF. The two branches are connected to source V subscript 1 through resistor R subscript 2 of 30 kΩ.
Got questions? Get instant answers now!

Consider the infinitely long chain of resistors shown below. What is the resistance between terminals a and b ?

The circuit shows infinitely long circuit with vertical resistor R and its two ends connected to horizontal branches with resistors R connected to vertical resistor R connected to horizontal branches with resistors R and so on..

R eq = ( 1 + 3 ) R

Got questions? Get instant answers now!

Consider the circuit below. The capacitor has a capacitance of 10 mF. The switch is closed and after a long time the capacitor is fully charged. (a) What is the current through each resistor a long time after the switch is closed? (b) What is the voltage across each resistor a long time after the switch is closed? (c) What is the voltage across the capacitor a long time after the switch is closed? (d) What is the charge on the capacitor a long time after the switch is closed? (e) The switch is then opened. The capacitor discharges through the resistors. How long from the time before the current drops to one fifth of the initial value?

The positive terminal of voltage source V of 12 V is connected to an open switch. The other end of the switch is connected to two parallel branches. The first branch has resistors R subscript 2 of 2 Ω and R subscript 2 of 4 Ω. The second branch has resistors R subscript 3 of 3 Ω and R subscript 4 of 3 Ω. The two branches are connected in the middle using capacitor C. The other ends of the branches are grounded.
Got questions? Get instant answers now!

A 120-V immersion heater consists of a coil of wire that is placed in a cup to boil the water. The heater can boil one cup of 20.00 ° C water in 180.00 seconds. You buy one to use in your dorm room, but you are worried that you will overload the circuit and trip the 15.00-A, 120-V circuit breaker, which supplies your dorm room. In your dorm room, you have four 100.00-W incandescent lamps and a 1500.00-W space heater. (a) What is the power rating of the immersion heater? (b) Will it trip the breaker when everything is turned on? (c) If it you replace the incandescent bulbs with 18.00-W LED, will the breaker trip when everything is turned on?

a. P imheater = 1 cup ( 0.000237 m 3 cup ) ( 1000 kg m 3 ) ( 4186 J kg °C ) ( 100 ° C 20 ° C ) 180.00 s 441 W ;
b. I = 441 W 120 V + 4 ( 100 W 120 V ) + 1500 W 120 V = 19.51 A ; Yes, the breaker will trip.
c. I = 441 W 120 V + 4 ( 18 W 120 V ) + 1500 W 120 V = 13.47 A ; No, the breaker will not trip.

Got questions? Get instant answers now!

Find the resistance that must be placed in series with a 25.0 - Ω galvanometer having a 50.0 - μ A sensitivity (the same as the one discussed in the text) to allow it to be used as a voltmeter with a 3000-V full-scale reading. Include a circuit diagram with your solution.

Got questions? Get instant answers now!

Find the resistance that must be placed in parallel with a 60.0 - Ω galvanometer having a 1.00-mA sensitivity (the same as the one discussed in the text) to allow it to be used as an ammeter with a 25.0-A full-scale reading. Include a circuit diagram with your solution.


The figure shows a circuit with two parallel branches, one with galvanometer connected to resistors r and other with resistor R. ,
2.40 × 10 −3 Ω

Got questions? Get instant answers now!

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply
Practice Key Terms 3

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, University physics volume 2. OpenStax CNX. Oct 06, 2016 Download for free at http://cnx.org/content/col12074/1.3
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'University physics volume 2' conversation and receive update notifications?

Ask