Q27 of 330 Page 38

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?

When two resistors are connected in series, their resultant resistance is given by

R= R1+R2


Here R1 = 2 ohm


R2= 3 ohm


Combined resistance, R = R1 + R2 = 2+3 = 5 ohm


(b) We know that the current, I= V/R


Here R = 5 ohm


V= 10V


I = 10/5 = 2 amp


(c) Potential difference across 2ohm resistor V= I x R1= 2×2=4V


(d) Potential difference across 3ohm resistor V= I x R2= 2×3=6V


More from this chapter

All 330 →
25

A p.d. of 4 V is applied to two resistors of 6 Ω and 2 Ω and 6 Ω connected in parallel. Calculate:

(a) the combined resistance


(b) the current flowing in the main circuit


(c) the current flowing in the 6Ω resistor.

 26

A p.d. of 6 V is applied to two resistors of 3Ω and 6Ω connected in parallel. Calculate:

(a) the combined resistance


(b) the current flowing in the main circuit


(c) the current following in the 3Ω resistor

 28

In the circuit given below:


(a) What is the combined resistance?


(b) What is the p.d. across the combined resistance?


(c) What is the p.d. across the 3 Ω resistor?


(d) What is the current in the 3Ω resistor?


(e) What is the current in the 6 Ω resistor?

 29

A 5 V battery is connected to two 20 Ω resistors which are joined together in series.

(a) Draw a circuit diagram to represent this. Add an arrow to indicate the direction of conventional current flow in the circuit.


(b) What is the effective resistance of the two resistors?


(c) Calculate the current that flows from the battery.


(d) What is the p.d. across each resistor?