Advertisements
Advertisements
प्रश्न
In the circuit diagram given below, three resistors R1, R2, and R3 of 5 Ω, 10 Ω and 30 Ω, respectively are connected as shown
Calculate:
- current through each resistor.
- total current in the circuit.
- total resistance in the circuit.
Advertisements
उत्तर
a. Let I1, I2 and I3 be the current flowing through the resistors of 5 Ω, 10 Ω and 30 Ω, respectively.
According to Ohm's law, V = IR
Here, V = 12 V and R = 5 Ω
`I = V/R`
`I_1 = 12/5 = 2.4 A`
`I_2 = 12/10 = 1.2 A`
`I_3 = 12/30 = 0.4 A`
b. Total current through the circuit, I = I1 + I2 + I3
= 2.4 A + 1.2 A + 0.4 A
= 4 A
c. The resistors of 5 Ω, 10 Ω and 30 Ω are connected in parallel. Therefore, the net resistance will be:
`1/ R = 1/R_1 + 1/R_2 + 1/R_3`
`1/R = (1/5) + (1/10) + (1/30)`
`1/R = (6 + 3 +1)/30`
`I/R = 10/30`
R = 3 Ω
APPEARS IN
संबंधित प्रश्न
Define the unit of current.
Draw the electrical symbols of the following components and state its use:
Rheostat (variable resistance)
What is the Flow of Charge Called?
One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor?
If the current through a floodlamp is 5 A, what charge passed in 10 seconds?
(a) 0.5 C
(b) 2 C
(c) 5 C
(d) 50 C
How many electrons are flowing per second past a point in a circuit in which there is a current of 5 amp?
In the circuit shown below, the voltmeter reads 10 V.
(a) What is the combined resistance?
(b) What current flows?
(c) What is the p.d. across 2 Ω resistor?
(d) What is the p.d. across 3 Ω resistor?
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a parallel circuit to an identical power supply line.
(b) In which circuit, if one bulbs be brighter?
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a parallel circuit to an identical power supply line.
(c) In which circuit, if one bulb blows out, all other will stop glowing?
Consider the circuit given below when A, B and C are three identical light bulbs of constant resistance. 
(a) List the bulbs in order of increasing brightness.
(b) If C burns out, what will be the brightness of A now compared with before?
(c) If B burns out instead, what will be the brightness of A and C compared with before?
A switch must be connected in:
(a) Live wire (b) neutral wire
(c) earth wire (d) either earth or neutral wire
Tick(✓) the correct choice in the following:
When the length of a conductor is doubled the resistance of the conductor
will
Complete the following table. The first answer has been given as an example
| Quantity | Unit |
|
(a) Electrical potential Volt ( b) Resistance ( c) Power ( d) Energy ( e) Resistivity |
Volt ........ .......... ............ .............. |
The following appliances are to be used on 240 V supply. Calculate the current used by each and say which fuse, 2 amp, 5 amp or 13 amp should be incorporated with each, (i) A television rated at 150 W, (ii) An electric iron rated at 750 W, (iii) An immersion heater rated at 3000 W, (iv) A hair dryer rated at 500 W. How much will it cost to run the television set for 100 days for an average of 4 hours a day at 60 paise per unit?
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
State whether true or false. If false, correct the statement.
Current can produce magnetic field.
The flow of electric charge per unit time is called potential difference.
