Q. A transformer has 200 turns in the primary coil and 50 turns in the secondary coil. If the primary voltage is 240 V, what is the secondary voltage? (2023)
A.
60 V
B.
120 V
C.
240 V
D.
480 V
Solution
Using the transformer equation Vp/Vs = Np/Ns, we find Vs = Vp × (Ns/Np) = 240 V × (50/200) = 60 V.
Q. A transformer operates on the principle of electromagnetic induction. If the primary coil has 100 turns and the secondary coil has 50 turns, what is the relationship between the primary and secondary voltages?
A.
V_primary = 2 * V_secondary
B.
V_primary = 0.5 * V_secondary
C.
V_primary = V_secondary
D.
V_primary = 4 * V_secondary
Solution
The voltage ratio in a transformer is given by the turns ratio. Therefore, V_primary/V_secondary = N_primary/N_secondary = 100/50 = 2, which means V_primary = 2 * V_secondary.
Q. A transformer operates on the principle of electromagnetic induction. What is the primary function of a transformer?
A.
To increase voltage
B.
To decrease voltage
C.
To convert AC to DC
D.
To store energy
Solution
A transformer is designed to increase or decrease the voltage in an AC circuit through electromagnetic induction, depending on the turns ratio of the primary and secondary coils.
Q. A transversal intersects two lines such that one of the interior angles is 120 degrees. What is the measure of the exterior angle at that intersection?
A.
60 degrees
B.
120 degrees
C.
90 degrees
D.
180 degrees
Solution
The exterior angle is supplementary to the interior angle. Therefore, the exterior angle = 180 - 120 = 60 degrees.
Q. A transversal intersects two parallel lines creating a pair of corresponding angles. If one of the angles measures 120 degrees, what is the measure of the corresponding angle?
A.
60 degrees
B.
120 degrees
C.
90 degrees
D.
30 degrees
Solution
Corresponding angles are equal when a transversal intersects two parallel lines. Therefore, the corresponding angle also measures 120 degrees.
Q. A transversal intersects two parallel lines creating a pair of corresponding angles. If one of the corresponding angles measures 60 degrees, what is the measure of the other corresponding angle?
A.
60 degrees
B.
120 degrees
C.
90 degrees
D.
180 degrees
Solution
Corresponding angles are equal when a transversal intersects two parallel lines. Therefore, the other corresponding angle is also 60 degrees.
Q. A transversal intersects two parallel lines creating a pair of corresponding angles. If one of the angles measures 60 degrees, what is the measure of the corresponding angle? (2019)
A.
60 degrees
B.
120 degrees
C.
90 degrees
D.
30 degrees
Solution
Corresponding angles are equal when a transversal intersects parallel lines. Thus, the corresponding angle is also 60 degrees.
Q. A tree is 15 meters tall. From a point on the ground, the angle of elevation to the top of the tree is 30 degrees. How far is the point from the base of the tree?
Q. A trophy costs $150 and is awarded to the top three students in a competition. If the total cost of the trophies is $450, how many trophies were purchased? (2020)
A.
1
B.
2
C.
3
D.
4
Solution
Total cost of trophies = $450. Cost per trophy = $150. Number of trophies = 450 / 150 = 3.
Q. A tuning fork produces a sound wave of frequency 440 Hz. What is the wavelength of the sound wave in air (speed of sound = 340 m/s)?
A.
0.77 m
B.
0.85 m
C.
0.90 m
D.
1.00 m
Solution
The wavelength λ can be calculated using the formula λ = v/f, where v is the speed of sound and f is the frequency. Thus, λ = 340 m/s / 440 Hz = 0.77 m.
