Y11 INTERVENTION : Electricity V=IR mains 1. 5 mins EXAM CONDITIONS demand 1 Question (grade 4/5) 5 mins go through mark scheme 2. 10 mins Walking talking demand 2 Question (grade 6/7) 3. 5 mins EXAM CONDITIONS demand 3 Question (grade 8/9) 5 mins go through mark scheme
A cell / battery gives a direct current 1. 5 mins 15 Y V = IR A cell / battery gives a direct current Or X and Z are AC V = 0.3 x15 4.5 V
Y11 INTERVENTION : Electricity V=IR mains 1. 5 mins EXAM CONDITIONS demand 1 Question (grade 4/5) 5 mins go through mark scheme 2. 10 mins Walking talking demand 2 Question (grade 6/7) 3. 5 mins EXAM CONDITIONS demand 3 Question (grade 8/9) 5 mins go through mark scheme
2. 10 mins The variable resistor increases/ decreases the current which increases / decreases the potential difference The temperature of the bulb ( filament) increases Cost: Hal cheaper to buy & cost more to run LEDs Last longer ( less maintenance) Power = IV Energy efficiency: LEDs are more (22% ) efficient LEDs produce less heat LEDs work with less current Power = 3 x 12 Power = 36 W
3. 5 mins V = I R V = R I 6 V = R 0.12 /1000A 50,000 ohm = R Body fat / resistance changes ( depends on age, gender fitness, bone density)
Incorrect value of body fat is obtained because High water content changes body resistance Cutting the cable causes a 100mA difference between Live and Neutral The RCCB switches the current off within 60 milliseconds ( very fast 1 mk only) A residual current circuit breaker detects the difference between LIVE and NEUTRAL A fuse overheats and melts
Y11 INTERVENTION : Electricity V=IR mains 1. 5 mins EXAM CONDITIONS demand 1 Question (grade 4/5) 5 mins go through mark scheme 2. 10 mins Walking talking demand 2 Question (grade 6/7) 3. 5 mins EXAM CONDITIONS demand 3 Question (grade 8/9) 5 mins go through mark scheme