Electric Circuits Answers

A cell supplies a current of 4.20 mA for 925 hours. What is its rating? 

The power dissipated in a resistor is 240 watts when a voltage of 220 volts is across it. If the voltage is cut in half, what is the power dissipation in the resistor?

A 12 ȍ resistor has a potential difference of 4.0 volts. Determine the power dissipated in the resistor. 

A 12 volt supply is in series with a resistor and an LDR. In light, the LDR has a potential difference of 3.0 volts and in the dark it has a potential difference of 6.0 volts. Find the ratio of the series resistor to the resistance of the LDR in light.  

The resistance of a certain length of wire is 12 ȍ. If the wire is replaced with another wire of the same substance but half the length and twice the diameter, what will be the new resistance?  

6.00 metres of a wire yields a resistance of 84.0 ȍ. If the resistivity of the wire is 4.30 × 10–7 ȍm, find the diameter of the wire. 

The potential difference across a component is 24 volts when the current through it is 0.40 amps. What is the resistance of the component?

An electron is accelerated to a speed of 4.23 × 10^6 ms –1 from rest by a potential difference. Calculate the potential difference

The power dissipated in a 6.0 V device is 3.0 watts. What current is flowing through the device?

A cell produces a steady current of 0.0044 A during its lifetime of 96 hours. Determine the maximum energy that this 1.5 V (terminal voltage) cell provides.