The current through a flashlight bulb is 40 mA and the total battery voltage is 4.5 V. The resistance of the bulb is approximately?
A.112 ohms
B.11.2 ohms
C.1.2 ohms
D.18 ohms
Description : How much resistance is required to limit the current from a 12 V battery to 3.6 mA? A.3.3 k ohms B.33 k ohms C.2.2 k ohms D.22 k ohms
Last Answer : How much resistance is required to limit the current from a 12 V battery to 3.6 mA? A.3.3 k ohms B.33 k ohms C.2.2 k ohms D.22 k ohms
Description : When there is 12 mA of current through a 1.2 k ohms resistor, the voltage across the resistor is? A.14.4 V B.1.4 V C.100 V D.10 V
Last Answer : When there is 12 mA of current through a 1.2 k ohms resistor, the voltage across the resistor is? A.14.4 V B.1.4 V C.100 V D.10 V
Description : Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 k ohms of resistance? A.27.2 mA B.59 mA C.5.9 mA D.590 mA
Last Answer : Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 k ohms of resistance? A.27.2 mA B.59 mA C.5.9 mA D.590 mA
Description : If current of 20 mA is passing through op-amp and voltage drop across series resistor is 10 V then value of resistance is A. 500Ω B. 400Ω C. 300Ω D. 200Ω
Last Answer : 500Ω
Description : Twelve volts are applied across a resistor. A current of 3 mA is measured. What is the value of the resistor? A.4 ohms B.400 ohms C.4 kohms D.4.4 ohms
Last Answer : Twelve volts are applied across a resistor. A current of 3 mA is measured. What is the value of the resistor? A.4 ohms B.400 ohms C.4 kohms D.4.4 ohms
Description : You are measuring the current in a circuit that is operated on an 18 V battery. The ammeter reads 40 mA. Later you notice the current has dropped to 20 mA. How much has the voltage changed? A.9 V B.900 mV C.0 V D.18 V
Last Answer : You are measuring the current in a circuit that is operated on an 18 V battery. The ammeter reads 40 mA. Later you notice the current has dropped to 20 mA. How much has the voltage changed? A.9 V B.900 mV C.0 V D.18 V
Description : Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open?
Last Answer : Three 60 W bulbs are in parallel across the 60 V power line. If one bulb burns open the other two bulbs will light.
Description : A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will?
Last Answer : A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will increase.
Description : Two light bulbs are connected in series across a 120 V battery. Bulb 1 uses 40 W of power and Bulb 2 uses 20 W of power. If bulb 1 alone is connected to the 120 V source, then it will consume (A) 90 W (B) 80 W (C) 60 W (D) 180 W
Last Answer : Two light bulbs are connected in series across a 120 V battery. Bulb 1 uses 40 W of power and Bulb 2 uses 20 W of power. If bulb 1 alone is connected to the 120 V source, then it will consume 90 W
Description : What is the capacitance when a capacitor passes a current of 31.43 mA when supplied with 40 V AC with a frequency of 1000 Hz? A) 0.125 F B) 0.125 μF C) 1257.2 μF D) None of these
Last Answer : What is the capacitance when a capacitor passes a current of 31.43 mA when supplied with 40 V AC with a frequency of 1000 Hz? A) 0.125 F B) 0.125 μF C) 1257.2 μF D) None of these
Description : How much resistance is needed to draw 17.6 mA from a 12 volt source? A.212 ohms B.6.8 kohms C.68 ohms D.680 ohms
Last Answer : How much resistance is needed to draw 17.6 mA from a 12 volt source? A.212 ohms B.6.8 kohms C.68 ohms D.680 ohms
Description : When converting 0.16 mA to microamperes, the result is? A.16 μA B.160 μA C.1,600 μA D.0.0016 μA
Last Answer : When converting 0.16 mA to microamperes, the result is? A.16 μA B.160 μA C.1,600 μA D.0.0016 μA
Description : How much voltage is needed to produce 2.5 A of current through a 200 ohms resistor? A.50 V B.500 V C.80 V D.8 V
Last Answer : 500 V
Description : When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is? A.12 V B.120 V C.240 V D.2,400 V
Last Answer : When the turns ratio of a transformer is 20 and the primary ac voltage is 12 V, the secondary voltage is? A.12 V B.120 V C.240 V D.2,400 V
Description : Four amperes of current are measured through a 24 ohms resistor connected across a voltage source. How much voltage does the source produce? A.960 V B.9.6 V C.96 V D.8 V
Last Answer : Four amperes of current are measured through a 24 ohms resistor connected across a voltage source. How much voltage does the source produce? A.960 V B.9.6 V C.96 V D.8 V
Description : If reading the AC voltage from a typical wall outlet, the range switch of the device illustrated should be set to ___________. EL-0047 A. 1,000 V B. 250 V C. R X 10,000 D. 10 ma/amps
Last Answer : Answer: B
Description : In the illustrated motor controller, the motor fails to start. A voltmeter reading between 1 and 6 reads line voltage, while the voltmeter reading between 2 and 6 reads 0 VAC. The problem is __________. EL- ... in the 'M' coil, 'Ma' contact/start switch or overload contacts D. fuse '10a' is blown
Description : In the circuit shown in Fig. 4.63, the terminal voltage of the battery is 6.0 V. Find the current I through the `18 Omega` resistor.
Last Answer : In the circuit shown in Fig. 4.63, the terminal voltage of the battery is 6.0 V. Find the current I through the `18 Omega` resistor.
Description : What determines the size battery needed (or used) in a device such as a flashlight?
Last Answer : How long might it be expected to last, like on a hunting trip, how compact is it /where will it be stored for potential use, how well will it fit the hand, what it’s expected use is/might be.
Description : The filament of an electric bulb is made of?
Last Answer : The filament of an electric bulb is made of tungsten.
Description : A resistance of 3.3 M ohms is connected across a 500 V source. The resulting current is approximately? A.15.1 μA B.151 μA C.66 mA D.660 mA
Last Answer : A
Description : A galvanometer has a coil of resistance `100 Omega` and gives a full-scale deflection for `30 mA` current. If it is to work as a voltmeter of `30 V` r
Last Answer : A galvanometer has a coil of resistance `100 Omega` and gives a full-scale deflection for `30 mA` current. ... Omega` C. `1000 Omega` D. `1800 Omega`
Description : The amount of current in a resistor needs to be changed from 120 mA to 160 mA by changing the 24 V source, the new voltage will be: A. 8 V B. 320 V C. 3.2 V D. 32 V
Last Answer : The amount of current in a resistor needs to be changed from 120 mA to 160 mA by changing the 24 V source, the new voltage will be: 32 V
Description : Output current from an LED is A. 20 mA B. 30 mA C. 40 mA D. 50 mA
Last Answer : 20 mA
Description : Op-amp can provide maximum output current of A. 25 mAB. 30 mA C. 35 mA D. 40 mA
Last Answer : 25 mA
Description : Current gain of a transistor which has collector current of 10 mA and a base current of 40 micro Ampere is: (a) 25 (b) 250 (c) 2500 (d) 25000
Last Answer : b) 250
Description : Three bulbs are rating 40W 60W and 100W designed to work on 220V mains. Which bulb will burn most brightly if they are connected in series across 220 V mains? a. 40 W bulb b. 60 W blub c. 100 W blub d. all will burn equally brightly
Last Answer : a. 40 W bulb
Description : If an incandescent lamp of 80 ohms resistance takes a current of 0.75 ampere, what voltage is required to light it? A.45 volts B.60 volts c.23 volts D.None of these
Last Answer : V=IR = 80*0.75 = 60 volts
Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A
Last Answer : D. 2.0 A
Description : If a voltage divider is required for a load that will use 450 mA of current, what should be the value of bleeder current?
Last Answer : 45 mA rule-of-thumb.
Description : Rated power of a bulb at V voltage is P. Now, same voltage V is applied in all conditions mentioned in Column I. Match this Column I with Column II in
Last Answer : Rated power of a bulb at V voltage is P. Now, same voltage V is applied in all conditions ... Column II in which actual total power consumed is given.
Description : Four members of a band are walking to a night concert. They decide to take a shortcut, but must cross a bridge. Luckily they have one flashlight. Because of the varying size of their instruments, it ... bridge and still get to the concert on time. What order should they cross to get eve -Riddles
Last Answer : First, the one minute person and the two minute person must cross the bridge, for a total of two minutes. Then the one minute person should come back with flashlight - total of three ... minutes) and gets the one minute person and they cross together bringing the total to seventeen minutes.
Description : When one leg of parallel circuit is opened out the total current will?
Last Answer : When one leg of parallel circuit is opened out the total current will decrease.
Description : A neon flashlight cell with an emf of 1.5V gives a current of 15A when connected directly to an ammeter of resistance 0.04?. Internal resistance of the cell is a. 0.0004? b. 0.06? c. 0.10? d. 0.13?
Last Answer : b. 0.06?
Description : If a circuit contains a 1.5 volts battery and a bulb with a resistance of 3 ohms. calculate the current?
Last Answer : Use Ohm's Law. Solving for current:I = V/R(current = voltage / resistance)
Description : In the illustrated circuit, what is the voltage of the battery if the resistance of R1 is 150 ohms, the total resistance is 250 ohms and the current though R2 is 25 milliamps? EL-0036 A. 12 volts B. 24 volts C. 1.5 volts D. 6.25 volts
Last Answer : Answer: D
Description : How many mA does the iPhone 3G and 3G[S] battery have?
Last Answer : 1150 mAh
Description : A battery is connected to a circuit containing three resistors in parallel. The values of the three resistors are 2 ohms, 3 ohms, and 6 ohms. What is the voltage of the battery if the total circuit current is 12 amps? A. 2 volts B. 6 volts C. 12 volts D. 24 volt
Last Answer : Answer: C
Description : Current in a 60 W light bulb when it is connected to a 230 V power supply is A. 0.26 A B. 1.5 A C. 2.6 A D. 3.9 A
Last Answer : 0.26 A
Description : Two series resistors are connected to an ac source. If there are 7.5 V rms across one resistor and 4.2 V rms across the other, the peak source voltage is? A.16.54 V B.1.65 V C.10.60 V D.5.93 V
Last Answer : Two series resistors are connected to an ac source. If there are 7.5 V rms across one resistor and 4.2 V rms across the other, the peak source voltage is? A.16.54 V B.1.65 V C.10.60 V D.5.93 V
Description : An electric heater draws 3.5 A from a 110 V source. The resistance of the heating element is approximately? A.385 ohms B.38.5ohms C.3.1 ohms D.31 ohms
Last Answer : 31ohns
Description : A galvanometer having a resistance of 4.5 Ω can read up to 5 mA. If it is to read 100 V, then the high resistance to be used in series will be a) 19998 Ω b) 19995.8 Ω c) 19995.5 Ω d) 19996.5 Ω
Last Answer : c) 19995.5
Description : A resistor of value R/2 is connected in parallel with a resistor of value R/3. The voltage drop across the parallel combination is V. The total current supplied by the voltage source is: w) 2 V/R (read: 2 V over R) x) 3 V/R (read: 3 V over R) y) 4 V/R (read: 4 V over R) z) 5 V/R (read: 5 V over R)
Last Answer : ANSWER: Z -- 5 V/R
Description : Why doesn't the wire get hot in a circuit going from a battery through a light bulb?
Last Answer : Actually the wire WILL get hot, but specifically HOW MUCH itgets hot depends on the current, and on the resistance of thewire.In most circuits, the resistance of the wire (and thus, theamount of heating) is insignificant, and can safely be ignored formost calculations.
Description : The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 ohms load. The turns ratio is 3:1. What is the secondary voltage? A.2 V B.20 V C.180 V D.18 V
Last Answer : The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 ohms load. The turns ratio is 3:1. What is the secondary voltage? A.2 V B.20 V C.180 V D.18 V
Description : The formula to find I when the values of V and R are known is? A.I = VR B.I = R/V C.V = IR D.I = V/R
Last Answer : The formula to find I when the values of V and R are known is? A.I = VR B.I = R/V C.V = IR D.I = V/R
Description : The average value of a 12 V peak sine wave over one complete cycle is? A.0 V B.1.27 V C.7.64 V D.6.37 V
Last Answer : The average value of a 12 V peak sine wave over one complete cycle is? A.0 V B.1.27 V C.7.64 V D.6.37 V
Description : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V
Last Answer : If the peak value of a sine wave is 30 V, the rms value is? A.19.08 V B.7.07 V C.0.707 V D.23.10 V
Description : Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as?
Last Answer : Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as 2 : 5.
Description : What amount of current will flow through resistance of 10 ohms when it is connected across a potential difference of 20 volts? A.30 amperes B.5 amperes C.10 amperes D.2 amperes
Last Answer : 2 amperes