Electric Circuits Answers

0.1 kg aluminum calorimeter contains 0.2 kg water at 70.6 °C. It is found that the temperature of the calorimeter and water drops to 20°C in 15 minutes. What is the rate of heat flow to the atmosphere?

Merlinda is heating 2-kg water initially at 6.5 °C using a 100-Watt solar-powered heater. How long will it take (in seconds) to reach the boiling point?

A microwave oven needs 240 V of electricity to operate and draws 5 A current. How much does it cost per month (30 days) if it operates 30 minutes per day and TNB char RM 0.95 cents per kWh?

A rechargeable battery has emf ε_battery​=14.0 V, internal resistance r=4.00 Ω and battery capacity (total charge) 2.00 Ah. 

When the battery is fully charged, a light bulb is connected to it for 8 hours (no other elements are in the circuit). The light bulb has specs 14.0 V and 1.00 W.

We assume the light bulb has constant resistance (independent of the current) and the emf of the battery remains constant.

After these 8 hours the battery is disconnected from the light bulb and connected in this circuit for charging:

Picture: +ε to +battery to -battery to resistor R₁ to -ε

The charger consists of a ideal voltage source with ε=20.0 V (with no internal resistance) and a resistor R₁​ in series.

(a) What is the minimum time that is needed to fully recharge the battery (with R₁​=0 Ω)

(b) What should the resistance R₁​ be to fully recharge the battery in exactly 1 hour?

Two charges q1 = -6 µC and q2 = +10 µC are placed 12 cm apart. Another charge, q=-2 μC is placed in the middle. Determine the magnitude and direction of the force acting on q3 by the charge q1 and q2.

Two charges q1 = -6 µC and q2 = +10 µC are placed 12 cm apart. Another charge, q=-2 μC is placed in the middle. Determine the magnitude and direction of the force acting on q3 by the charge q1 and 92.

plot a graph of voltage against current and find the slope, the slope you find from voltage to current is the resistance which is measured in ohm's.

the standard error on slope is given as 4(V2-V1)/6(12-11)

A 35 W radio is on for 2.5 h. If the voltage across the radio's terminals is 120 V, how much total charge moves through the radio while it is on?

Three 2100 Ω resistors, all in parallel, are connected across a 210-V dc source. Calculate (a) the

total current, (b) the current through each resistor, and (c) the total power dissipated in the resistors.

A flat circular disk of radius "a" is placed inside a uniform external electric field E' pointing in positive z direction. calculate the net electric flux through the disk.