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
Complete the following :-
(a)
Write any two characteristics of a series combination of resistors.
Name the material which is the best conductor of electricity.
A p.d. of 4 V is applied to two resistors of 6 Ω and 2 Ω connected in series. Calculate:
(a) the combined resistance
(b) the current flowing
(c) the p.d. across the 6 Ω resistor
If two resistors of 25 Ω and 15 Ω are joined together in series and then placed in parallel with a 40 Ω resistor, the effective resistance of the combination is :
(a) 0.1 Ω
(b) 10 Ω
(c) 20 Ω
(d)40 Ω
The diagram below shows part of a circuit:
If this arrangement of three resistors was to be replaced by a single resistor, its resistance should be:
(a) 9 Ω
(b) 4 Ω
(c) 6 Ω
(d) 18 Ω
In series combination of resistances ______.
Define the term resistivity and state its S.I. unit. Which will have higher resistivity a conductor or an insulator.
Two resistors of 4Ω and 6Ω are connected in parallel to a cell to draw 0.5 A current from the cell. Calculate the current in each resistor.
What should be the length of a nickel wire of area of cross-section 3 mm2 used for making a rheostat of 750 ohm? (ρ of nickle = 0.069 Ohm mm2/m)
