This set of Farm Machinery Multiple Choice Questions on “Harrows”.
1. The flanged tube, mounted on the gang axle between every two discs to retain them at fixed position laterally on the shaft is called ______
a) Spool
b) Gang
c) Bearing
d) Scraper
Answer: a
Explanation: Spool is just a device for keeping the discs at equal spacing on the axle. It is usually cast in special shapes and sizes and is generally made of cast iron.
2. Which disc harrow has two gangs in tandem and two fitted one behind the other?
a) Tractor drawn
b) Off set
c) Tandem
d) Double action
Answer: b
Explanation: Offset Disc harrow has two gangs in tandem and two fitted one behind the other. The discs of both gangs face in opposite directions.
3. What is the size of the discs in tractor drawn disc harrows?
a) 20-30 cm diameter
b) 10-30 cm diameter
c) 90-110 cm diameter
d) 35-70 cm diameter
Answer: d
Explanation: Disc is a circular, concave revolving steel plate used for cutting and inverting the soil. Disc is made of high grade heat treated hardened steel. Tractor drawn disc harrows have concave discs of size varying from 35 to 70 cm diameter.
4. What is the weight of the disc harrow?
a) 80 to 100 kg
b) 30 to 50 kg
c) 10 to 40 kg
d) 23 to 56 kg
Answer: a
Explanation: Usually transport wheels are provided for easy movement of the harrow from place to place. The size of the harrow is determined by the maximum width of cut of the soil. The weight of the disc harrow varies between 80 to 100 kg.
5. What is the range of the gang angle?
a) 29°-39°
b) 34°-56°
c) 0°-27°
d) 89°-100°
Answer: c
Explanation: The lever of the gang angle mechanism is usually made of mild steel flat with wooden handle. The gang angle can be adjusted approximately in the range from 0° to 27° only.
6. Which harrow is known as knife harrow?
a) Patela
b) Spring tooth harrow
c) Triangular harrow
d) Acme harrow
Answer: d
Explanation: Acme harrow is a special type harrow having curved knives also known as knife harrow. The front part of the knife compacts the soil and crushes the clods. A good pulverisation is obtained by this harrow easily.
7. How many acres can be covered by a harrow of 1.5 m width in a day of 8 hours with bullock power. If each spike of the harrow is giving 1 kg resistance when there are 50 spikes. What power would be necessary for the bullocks to pull the harrow?
a) 0.544 KW
b) 0.987 KW
c) 0.123 KW
d) 0.333 KW
Answer: a
Explanation: Area covered/hr = 1.5*4*1000 m3
Area per 8 hours = 6000*8 m2 = 4.8 ha
Total draft = 50 kg
Power, KW = (frac{Draft*speed}{1000}=frac{50*9.8*4*1000}{60*60*1000}) = 0.544.
8. What power is necessary for pulling a harrow with 50 times, each giving a resistance of 1 kg, when the speed of harrow is 5km/hr.
a) 0.980 KW
b) 0.223 KW
c) 0.680 KW
d) 1.902 KW
Answer: c
Explanation: Total soil resistance = 50 kg
Power = (frac{soil , resistance*speed}{1000}=frac{50*9.8*5*1000}{1000*60*60}) = 0.680 KW.