1. What is the name of the chemical solution used in a battery for chemical reactions?
a) Container
b) Terminal wires
c) Electrolyte
d) Separators
Discussion
Explanation: Electrolyte is the chemical solution used in a battery for chemical reaction. Usually this consists of about 35% sulphuric acid and 65% distilled water by weight with a specific gravity of 1.280 in fully charged condition. The electrolyte level should be 12 to 14 mm above the top edge of the plate.
2. What should be the minimum specific gravity after which the electrolyte should be charged?
a) 1.225
b) 1.335
c) 2.334
d) 1.123
Discussion
Explanation: Specific gravity of the electrolyte should be checked at suitable interval. If the specific gravity is below 1.225, it should be charged.
3. How much spark per minute is required by an eight-cylinder engine running at 4000 rpm?
a) 10000
b) 12000
c) 16000
d) 20000
Discussion
Explanation: 4000*4 = 16000 [because it is an eight-cylinder engine]
4. What are the types of spark plug?
a) Cold plug
b) Hot plug
c) Hot and Cold plug
d) Plug
Discussion
Explanation: Cold plug has a short insulator extending into the cylinder. The short path dissipates heat quickly, so it is named as cold plug. Hot plug has a comparatively longer insulator, so the heat has to pass through a longer path.
5. What percent of battery loss in 24 hours is known as battery leakage?
a) 2%
b) 3%
c) 1%
d) 1.5%
Discussion
Explanation: Battery leakage is considered excessive if the battery loses more than 1% of its capacity during 24 hours. To avoid this loss, battery cells should be regularly cleaned.
6. Which device is used to generate an electric current for producing spark in I.C. engine?
a) Magneto
b) Dynamo
c) Condenser
d) Plates
Discussion
Explanation: A magneto is used to generate an electric current for producing spark in I.C. engine. A high-tension magneto generates very high voltage needed for spark plug.
7. The process of igniting fuel by heat of compression is called?
a) Cooling ignition method
b) Compression ignition method
c) Compression initial method
d) Specific gravity method
Discussion
Explanation: Process of igniting fuel by heat of compression is known as compression ignition method. Diesel engine is a compression ignition engine. In this method, no electrical accessory is needed for ignition purpose.
8. Which device is used to control the quantity of oil circulation and to maintain correct pressure in the lubricating system?
a) Relief valve
b) Grease
c) Crankcase breather
d) By pass filter
Discussion
Explanation: Relief valve is provided to control the quantity of oil circulation and to maintain correct pressure in the lubricating system. The valve consists of a ball, held in place over an opening by an adjustable spring.
9. Two pulleys are connected by a belt. The sum of the diameter of two pulleys is 90 cm and while the one makes 50 rpm, the other makes 20 revolutions. What will be the diameter of the pulleys?
a) 19.7cm, 70.3 cm
b) 23.4 cm, 68.7 cm
c) 25.7 cm, 64.3 cm
d) 21.1 cm,63.2 cm
Discussion
Explanation: D1 + D2 = 90cm
Or, 50 * D1 = 20 * D2
Or, D2 = 2.5 D1
Now, D1 + 2.5 D1 = 90
D1 = 25.7 cm
D2 = 64.3 cm
10. Two pulleys are connected by a belt. The sum of the diameters of the pulleys is 92.6 cm and while one makes 50 rev/min the other make 200 rev/min. What will be the diameter of the pulleys?
a) 18.53 cm, 74.07 cm
b) 19.65 cm, 64.89 cm
c) 20.01 cm, 78.09 cm
d) 17.69 cm, 69.90 cm
Discussion
Explanation: D1 + D2 = 92.6 cm
D1N1 = D2N2
50(92.6 – D2) = D2 * 200
D2 = 18.53 cm
D1 = 74.07 cm