2019 KCSE Marking Scheme

2019 KCSE physics paper 1 marking scheme

1. Actual reading= 0.38mm
   ( error) = 0.03 -Meter reading = 0.35mm ✓
2. On sucking air rushes into the straw ✓ through the hole making it difficult ✓ to reduce pressure in the straw by sucking
3. – Using detergents/impurities
   – Raising the temperature
4. The flask absorbs heat from the hands and first expands✓ hence lev­el of liquid ✓ which expands more than the glass causing the rise. ✓
5.  Wax on rod B drops off first. ✓
   The thicker rod conducts heat faster than the thinner one. ✓

2019 KCSE physics paper 2 marking scheme

2. An uncharged conductor will also cause a decrease on the divergence of the leaf.
OR
Both positively charged conductor and an uncharged body cause a de­crease in divergence.

3. – Do not cross one another.
– They are complete loops.
– Direction of field is from North to South.
They are normal to the surface at the poles.
Closer at the poles and further apart away from the poles. Any two ✓

4 (b) – Increasing the number of turns in the coil. ✓
– Increasing the current ( or number of cells). ✓

8. – To sterilize medical equipment ✓
– To kill cancerous cells and malignant growths in the body. ✓
9. During the first half cycle of the input signal, current flows in the first diode, ✓
During the second half cycle of the input signal, current flows in the sec-ond diode, ✓
When the currents through the two diodes are combined a fully rectified wave signal is obtained as the output signal. ✓
10. By increasing the heating current in order to produce more electrons. ✓ Increasing the filaments current.
Increasing the temperature of the cathode.
11. – Fuse in the neutral wire ✓ instead of the live wire.
– Switch to lamp on the neutral ✓ wire instead of live wire.
– Connection of lamp B on Live wires only.
12. Alpha particle. ✓
13. Shows the object as being further than it actually is. ✓
Shows diminished images.
14l Infrared ✓

2019 KCSE physics paper 3 marking scheme

QUESTION2
PART A MARKING SCHEME

a) Centimeter mark = 50.1cm

b) (i) d = 11.3 cm

d = 0.113m

c) (i) V=17cm3

ii) V1 = 19.5cm3 d1 = 10cm