511. The work function for the silver surface is 4.73 eV. Find the minimum frequency that light must have to eject electrons from this surface (h = 6.63 × 10-34 Js)?
(A) 1.14 × 10^23 Hz
B) 1.14 × 10^15 Hz
(C) 3.14 × 10^23 Hz
(D) None of the above
512. A Kilowatt-hour is a unit of?
A) Energy
(B) Power
(C) Voltage
(D) Time
513. Energy gap in a semiconductor is?
(A) More than that of an insulator.
B) Less than that of an insulator.
(C) Equal to that of an insulator.
(D) None of the above
514. The mass of oxygen is 32 u (atomic mass unit). How many molecules of oxygen are in 32 g of oxygen?
A) 1 × (6.022 × 10^23) molecules
(B) 1 × (6.022 × 10^18) molecules
(C) 1/2 × (6.022 × 10^23) molecules
(D) 1/2 × (6.022 × 10^22) molecules
515. If the driver in the bus you are traveling in suddenly accelerates?
(A) You remain where you were.
B) You are pushed backward.
(C) Insufficient information.
(D) You are thrown forward.
516. A 200 kg motorcycle traveling at 30 m/s hits a tree and is brought to rest in 0.10 seconds. What is the magnitude of the average force acting on the car to bring it to rest?
(A) 6 × 10^3 N
(B) 6 × 10^5 N
C) 6 × 10^4 N
(D) 6 × 10^2 N
517. A sphere of radius r has volume v. If the radius of a sphere is increased to three times r, what is the volume now?
(A) 27 V
(B) 9 V
(C) 3 V
D) 2 V
518. 2 parallel wires carrying currents in the opposite directions?
(A) Attract each other
(B) They cancel out their individual magnetic fields
(C) Have no effect upon each other
D) Repel each other
519. The water’s velocity at the tube is (Take g = 9.8 m/s²) if it falls 19.6 meters into a turbine wheel from a dam.
A. 9.8 m/s
B. 19.6 m/s
C. 39.2 m/s
D. 98.0 m/s
520. The projectile has a range of R when the projection angle is 30 degrees. The other projection angle has the same value for the same range:
A. 45 Degree
B. 60 Degree
C. 50 Degree
D. 40 Degree
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