Changing current
Current rises linearly from 0.5 A to 3.5 A in 6.0 s. Find charge transferred.
STRUCTURED PRACTICE
Electricity
Attempt each visible question before revealing support.
Drift speed
Find v for I = 1.5 A, n = 8.5×10²⁸ m⁻³, A = 1.0×10⁻⁶ m² and q = 1.60×10⁻¹⁹ C.
Energy per charge
A component transfers 36 J when 4.0 C passes. Find p.d. and energy for one electron.
Ohmic evidence
A device gives (V,I): (2,0.10), (4,0.20), (6,0.30). Find R and assess Ohm's law.
I–V graph
An I-against-V graph has tangent gradient 0.040 A V⁻¹. Find resistance at that region.
Copper wire
A wire has L = 4.0 m, diameter 0.50 mm and ρ = 1.7×10⁻⁸ Ω m. Find R.
Heater energy
A 230 V heater draws 8.0 A for 12 min. Find power and energy.
Temperature response
Explain why heating raises a metal's R but lowers an NTC thermistor's R.