Problem 1: A battery has an emf of 12.8 V and
supplies a current of 3.2A. What is the resistance of the circuit? How many
coulombs leave the battery in 5 minutes?
Problem 2: A carbon electrode has a resistance of
The temperature coefficient of carbon is -0.0005 at 20oC. What will
be the resistance of electrode at 85oC?
Problem 3: Calculate the resistance of wire 10 m long that has a diameter of 2 mm and resistivity 2.63 * 10-2 Ω m.
A typical 12 V automobile battery has a resistance of 0.012 Ω. What is the
terminal voltage of this battery when the starter draws a current of 100 A.
Also calculate R, P, PR and Pr.
A 10 watt resistor has a value of 120 Ω. What is rated current through the
Problem 6: A resistor of 50 Ω has a P.D of 100 V, D.C. across 1 hour. Calculate (a) power and (b) energy.
Problem 7: Calculate the current through a single loop circuit if ε = 120 V , R = 1000 and internal resistance r = 0.01 ohms.
Problem 8: Find the current flowing through
the resistors of the fig.
Problem 10: Find the terminal potential
difference of each cell in the circuit.
Problem 11: The voltmeter in the circuit to the right may be considered to ideal. The values are 15.0 V , internal resistance r = 5.00 Ω, R1 = 100 Ω and R2 = 300 Ω. Calculate the current through R1.
Example Numerical Problems from the text
- Example 12.1: Each second 1018 electrons flow from right to left across a cross section of wire attached to the two terminals of a battery. (a) Calculate the current in the wire. (b) In which direction the current is flowing? See Solution
- Example 12.2: The high voltage in a TV receiver is 17 KV. The maximum allowable current is 150 micro ampere. What is the least permissible value of load resistance? See Solution