Advertisements
Advertisements
प्रश्न
Two lamps of resistance 30Ω and 20Ω respectively are connected in series in a 110V circuit. Calculate:
(i) the total resistance in the circuit
(ii) the current in the circuit, and
(iii) the voltage drop across each lamp.
Advertisements
उत्तर

(i) Since the two lamps are connected in series, their total resistance R is given by:
R = R1 + R2
= 30 Ω + 20 Ω = 50 Ω
(ii) We have, V = 110 volt, R = 50 Ω
∴ By Ohm's law
I = `"V"/"R" = 110/50`A = 2.2 A
(iii) We now have
I = 2.2 A
∴ V1 = IR1 = 2.2 × 30V = 66 V
∴ Voltage frop across L1 = 66 V
Similarly, V2 = IR2 = 2.2 × 20 = 44 V
∴ Voltage drop across L2 = 44 V.
संबंधित प्रश्न
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is ______.
Find the equivalent resistance between points A and B.

Two resistors of 4Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
(i) Draw a labelled circuit diagram showing the above arrangement.
(ii) Calculate the current in each resistor. What is an Ohmic resistor?
An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:
(a) 0.92 A
(b) 2.9 A
(c) 9.2 A
(d) 92 A
Give the law of combination of resistances in series.
What is the equivalent resistance between A and B in the given circuit (Fig?)

What do you mean by power rating of an electrical appliance? How do you use it to calculate
(a) the resistance of the appliance and
(b) the safe limit of the current in it, while in use?
State expression for Resistance connected in series.
2Ω resistor A, 1Ω resistor B and 4Ω resistor C are connected in parallel. The combination is connected across a 2V battery of negligible resistance. Draw the diagram of the arrangement and calculate:
(i) The current in each resistor A and C,
(ii) The current through battery.
What is the maximum resistance which can be made using five resistors each of `1/5` W?
