1671. A fuse in an electric circuit is used to _______.
A. When there is too much current flowing through the circuit, cut it off *
B. Control how the voltage changes in the circuit.
C. increase the circuit’s current flow.
D. Reduce the circuit’s current flow.
1672. What does angstrom measure_____.
A. Intensity of light
B. Length of light waves *
C. Volume of liquids
D. Speed of flowing water
1673. Why do electric power transmissions make use of transformers?
A. Because they speed up transmission
B. Because they can conserve electrical energy
C. Because they can lessen transmission losses *
D. Because they aid in the efficient distribution of electrical energy
1674. Which of the following controls the chain reaction in a nuclear reactor?
A. Active hydrogen
C. Molecules of high energy *
1675. Which of the following instruments is used for detecting and measuring small electric currents?
C. Galvanometer *
1676. Who discovered the law of attraction and repulsion between electric charges?
A. Coulomb *
B. Graham bell
1677. Why does water boil below 100 Degree Centigrade at higher altitudes?
A. Higher altitudes have a lower rate of heat loss.
B. Higher altitudes have more pure water than lower altitudes do
C. Clean air at higher altitudes makes fuel use more energy-efficient.
D. Higher altitudes have a lower atmosphere pressure than sea level.*
1678. Which of the following instruments is used for precise measurement of refractive indices?
A. Spectrometer *
1679. Frost is not formed generally on cloudy nights, reason?
A. There is no water vapour in the air
B. Clouds make air currents and disturbances that don’t make it cold
C. Clouds block radiation, which keeps the ground temperature higher *
D. The clouds have taken away the moisture in the air.
1680. Lightning is caused when______.
A. Similar electric charges collide with one another
B. Contrast charges in different clouds break down the resistance provided by the air between them
C. Clouds strike airborne impurities, causing a huge friction flare-up
D. The Earth pulls on the floating clouds