Everyday science results

Exercise and reference answers

Matching pairs

1. Left

   Neutral water at 25°C: pH

   Right

   7

2. Left

   Bell fades as air is removed

   Right

   Sound needs a material medium

3. Left

   Straw looks bent in water

   Right

   Refraction

4. Left

   Solenoid: turns ×2, current ÷2

   Right

   Same magnetic-field strength

5. Left

   6 Ω and 3 Ω parallel, 6 V

   Right

   3 A total; 18 W

6. Left

   Blue litmus in aqueous acid

   Right

   Turns red

Instructions

Coil length/core fixed; resistance constant.