High power electrical appliances are those which draws high current. The thinner the wire (smaller cross-sectional area), the higher the resistance of the cable which brings the current into the electrical appliances.   More thermal energy will be generated due to this higher resistance in the cable. The cable might be too hot or catch fire. So it is advisable to have thicker cables for high power electrical appliance as thicker cables have lower resistance.

Solutions: Option B Without the current in the river, the time taken for the swimmer to reach Q is 50s. This is based on the vertical constant speed of 1.2 m/s and veritcal (width of river) distance. With the current, which is constant 1.0 m/s, the swimmer will be drifted downstream. But the time taken to reach R from P is still 50s. So with the same 50s, you can calculate the horizontal distance based on the horizontal current speed of 1.0 m/s.

Solutions: Option B Key concepts: Both balls are free-falling, hence both will experience the same acceleration due to gravity 10 m/s2.

Solutions: Option B