A-Level Physics: Electricity and Fields Practice

A resistor has a resistance of 47 Ω and a current of 0.25 A flows through it. Calculate the power dissipated.

A wire of length 2.5 m, cross-sectional area 1.2 × 10⁻⁶ m², has resistivity 1.7 × 10⁻⁸ Ωm. Find its resistance.

A battery of EMF 12 V and internal resistance 0.5 Ω is connected to an external circuit of resistance 5.5 Ω. Find the terminal p.d.

Two resistors of 6 Ω and 12 Ω are connected in parallel across a 24 V supply. Find the total current drawn from the supply.

A potential divider consists of two 10 kΩ resistors in series across a 12 V supply. A load of 10 kΩ is connected across one of the resistors. Find the voltage across the load.

Apply Kirchhoff's second law to find the current through a 4 Ω resistor in a circuit with two cells: 10 V in series with 2 Ω, and 6 V in series with 4 Ω, both connected in parallel opposing each other.

Two point charges of +3 μC and -3 μC are placed 0.2 m apart in a vacuum. Find the electric field strength at the midpoint between them. (ε₀ = 8.85 × 10⁻¹² F/m)

A 470 μF capacitor is charged to a p.d. of 24 V. Calculate the energy stored.

An electron (charge 1.6 × 10⁻¹⁹ C, mass 9.11 × 10⁻³¹ kg) is accelerated from rest through a p.d. of 5000 V. Find its final speed.

A straight wire of length 0.3 m carries a current of 5 A in a magnetic field of flux density 0.4 T perpendicular to the wire. Find the force on the wire.

A proton (charge 1.6 × 10⁻¹⁹ C, mass 1.67 × 10⁻²⁷ kg) enters a magnetic field of 0.5 T perpendicular to its velocity of 3 × 10⁶ m/s. Find the radius of its circular path.

A coil of 200 turns and cross-sectional area 0.01 m² is placed in a magnetic field that increases from 0.2 T to 0.8 T in 0.05 s. Find the average EMF induced.

A radioactive isotope has a half-life of 8 hours. Starting with 80 g, how much remains after 32 hours?

Complete the nuclear equation: ²³⁵₉₂U → ²³¹₉₀Th + ___

Calculate the binding energy per nucleon of helium-4 given its mass defect is 0.0304 u. (1 u = 931.5 MeV/c²)