1. What would be the resonant frequency of an LRC circuit with L= 25 mH, C= 30 u

Question

1. What would be the resonant frequency of an LRC circuit with L= 25 mH, C= 30 uF AND R = 15 ohms?

a) 53 MHz

b) 1150 Hz

c) 60 Hz

d) 180 Hz

e) 120 Hz

2. As viewed from underwater, at what angle from the vertical does the sun appear to set?

a) 90 degrees

b) 45 degrees

c) 0 degrees

d) 49 degrees

e) 41 degrees

3. The critical angle for glass in air if the glass has index of refraction 1.5 is

a) 41.8 degrees

b) 85.9

c) 56.3

d) 48.1

e) 90

4. An object is placed 100 cm in front of a diverging lens of focal length -25 cm. A converging lens of
focal length 33 1/3 cm is placed 30 cm past the first lens. Where is the final image formed?
A) 3 meters before the second lens
B) 3 cm before the second lens
C) 30 cm after the second lens
D) 100 cm after the second lens
E) 20 cm in front of the first lens

PLEASE SHOW WORK OR NO POINTS

Explanation / Answer

1/ w= 1/sqrt(LC) = 1/sqrt(30*25*10^-9) = 180 Hz

b. b) 45 degrees

c.

so 1/v1 - 1/u1 = 1/f1

1/v1 + 1/100 = -1/25

so v1 = -20 cm

i.e. to the left of the diverging lens

now u2 = -(20+30) = -50cm

f2 = 33.33 cm

so1/v2 - 1/u2 = 1/f2

so 1/v2 + 1/50 = 1/33.33

so v2 = 100cm

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.