複選題

14. In a region where there is an electric field E and a magnetic field B, a charged particle is observed to travel straight without deflection. What is the speed of the particle if the fields are perpendicular to each other?
(A) E+B
(B) B/E
(C) EB
(D) 1/(EB)
(E) E/B 

10. A cylinder containing a gas at 400 K is fitted with a piston, allowing the gas to do 200 J of work during an isobaric expansion. Calculate the change in internal energy if 50 J of heat is lost to the surroundings. (A) 150 J (B) -50 J (C) -250 J (D) 50 J (E) 200 J

11. What is the entropy change when 18 grams of water at 100°C and 1 atm is completely converted to steam at the same temperature and pressure? (The latent heat of vaporization of water is 2260 kJ/kg) (A) 12.6 J/K (B) 25.2 J/K (C) 75.6 J/K (D) 109.2 J/K (E) 252.0 J/K 

12. A point charge q is placed at the center of a non-conducting spherical shell of inner radius r₁ and outer radius r₂. What is the electric field at a distance r from the center where r₁<r<r₂? (A) (B)(C) 0 (D)(E)

13. A rectangular loop of wire lies in the xy-plane with current I flowing in a clockwise direction when viewed from the positive z-axis. The loop dimensions are a along the x-axis and b along the y-axis. A uniform magnetic field B₀ along the positive z-direction is applied in the region. Using Ampere's Law, determine the net magnetic field at the center of the loop. (A) B₀ along the positive z-direction (B) B₀ along the positive x-direction (C) B₀ along the negative y-direction (D) B₀ along the negative z-direction (E) 0 

15. A solenoid with a core of relative permeability μr has 300 turns, a length of 0.5 meters, and carries a current of 2 A. If the permeability of free space is μ₀, what is the magnetic field inside the solenoid? (A) 600μ₁μ₀/0.5 (B) 300μ₁μ₀/0.5 (C) 600μ₁μ₀/2 (D) 0.5μ₁μ₀/600 (E) 0.5μ₁μ₀/300

1.比流器二次側短路時，其一次側電流值(A)不一定(B)不變(C)增大(D)減少。

2.往復式壓縮機油壓偏低，其可能的原因為(A)低壓過低(B)軸承磨損(C)高低壓差太小(D)高壓太低。

3.有一送風機轉速增加時，其風量(A)增加(B)不變(C)減少(D)無關。

4.為考量減少選用壓縮機排氣量時，下列何者係有關冷媒敘述為較大者？(A)單位比體積製冷量(B)單位質量製冷量(C)單位冷凝熱負荷(D)單位耗能。

5.依據公共工程製圖標準圖例，符號表示：(A)回風口(B)排風口(C)線形出風口(D)送風口。