A Newton
B Einstein
C Maxwell
D Bohr
Explanation: Einstein used photon theory to explain photoelectric effect.
A lambda = h/mv
B lambda = mv/h
C lambda = h/m
D lambda = hv/m
Explanation: lambda = h/p = h/mv, wave-particle duality.
A All element spectra
B Hydrogen line spectrum
C Continuous spectra
D X-ray spectra
Explanation: Bohr\'s model explained the hydrogen line spectrum.
A Excite electron
B Remove electron from surface
C Accelerate proton
D Ionize gas
Explanation: Work function is minimum energy to eject surface electron.
A E = h nu
B E = mv2
C E = mc2
D E = Fd
Explanation: E = h nu, where h is Planck\'s constant.
A 8 J
B 16 J
C 32 J
D 4 J
Explanation: KE = ½ mv² = ½ × 2 × 4² = ½ × 2 × 16 = 16 J
A 10 m/s
B 15 m/s
C 20 m/s
D 25 m/s
Explanation: v = u + at = 0 + 2 × 5 = 10 m/s
A 20 J
B 200 J
C 50 J
D 100 J
Explanation: W = mgh = 10 × 10 × 2 = 200 J
A 2 m/s²
B 50 m/s²
C 20 m/s²
D 100 m/s²
Explanation: a = v²/r = 100/5 = 20 m/s²
A 30 kg·m/s
B 11 kg·m/s
C 36 kg·m/s
D 1.2 kg·m/s
Explanation: p = mv = 5 × 6 = 30 kg·m/s
A 20 m/s²
B 5 m/s²
C 12 m/s²
D 8 m/s²
Explanation: a = F/m = 10/2 = 5 m/s²
A 170 Hz
B 680 Hz
C 342 Hz
D 1700 Hz
Explanation: f = v/λ = 340/2 = 170 Hz
A Air
B Water
C Vacuum
D Steel
Explanation: Sound is a mechanical wave and requires a medium to propagate; it cannot travel through vacuum.
A Pascal
B Newton
C Joule
D Watt
Explanation: Pressure = Force/Area, so SI unit is N/m² = Pascal (Pa)
A 20 cm
B 10 cm
C Infinite
D 5 cm
Explanation: By mirror/lens formula 1/f = 1/v + 1/u → 1/10 = 1/v + 1/20 → v = 20 cm
A V = IR
B V = I/R
C I = VR
D R = VI
Explanation: Ohm\'s law states that the voltage across a conductor is directly proportional to the current flowing through it, V = IR.
A 10 Ω
B 2.4 Ω
C 24 Ω
D 5 Ω
Explanation: 1/R = 1/4 + 1/6 = (3+2)/12 = 5/12 → R = 12/5 = 2.4 Ω
A 10 A
B 2.5 A
C 4 A
D 0.25 A
Explanation: I = V/R = 20/5 = 4 A
A Joule
B Watt
C Newton
D Pascal
Explanation: Energy has the same unit as work, which is Joule (J)
A Maximum
B Zero
C Negative
D Same as initial
Explanation: At the highest point of vertical motion, the instantaneous velocity becomes zero before the body starts falling down.