Light bends around sharp corners as a result of DIFFRACTION

Q-1: Light bends around sharp corners as a result of

1) refraction
2) reflection
3) diffraction
4) dispersion
ANSWER: 3 -- DIFFRACTION

Q-1:  A light ray traveling from glass into air strikes the glass-air surface at an angle 50 degrees to the normal. If the critical angle for the glass-air combination is 42 degrees, the percentage of light reflected from the surface is

1) 6
2) 25
3) 38
4) 100
ANSWER: 4 -- 100

Q-3: In the Millikan oil-drop experiment the UPWARD force on the drop is due to the:

1) gravitational and electric fields
2) gravitational field and the charge on the drop
3) electric field and the size of the drop
4) electric field and the charge on the drop
ANSWER: 4 -- ELECTRIC FIELD AND THE CHARGE ON THE DROP

Q-4:  In changing from an energy state of -1.51 electron-volts to -3.40 electron-volts, an atom emits a photon whose energy is:

1) 1.51 electron-volts
2) 1.89 electron-volts
3) 3.40 electron-volts
4) 4.91 electron-volts
ANSWER: 3 -- 1.89 ELECTRON-VOLTS

Q-5:  In an elastic collision, the RELATIVE velocities of separation of the two bodies after impact compared with the relative velocity of approach before impact is:

1) always greater
2) always smaller
3) always the same
4) first greater, then smaller
ANSWER: 3 -- ALWAYS THE SAME

Q-6: Two hockey pucks, of unequal mass and connected by a spring of negligible mass, rest on a horizontal frictionless surface. The spring is released, and the pucks move apart. The center of mass of the two pucks does one of the following. Does it:

1) move in a circle
2) move in the direction of the greater mass
3) remain stationary
4) move in the direction of the smaller mass
ANSWER: 3 -- REMAIN STATIONARY

Q-7:  A 500 kilogram car moving at 20 meters per second strikes a stone wall and is brought to a halt in 0.1 second. The average force of the car on the wall during impact is:

1) 10 Newtons
2) 1000 Newtons
3) 10,000 Newtons
4) 100,000 Newtons
ANSWER: 4 -- 100,000 NEWTONS

Q-8:  A bullet is fired with a muzzle velocity of 1000 meters per second from a rifle clamped to a window 4.9 meters above ground level. Neglecting air resistance, the horizontal distance from the rifle at which the bullet will strike the ground is

1) 4.9 meters
2) 500 meters
3) 1000 meters
4) 4900 meters
ANSWER: 3 -- 1000 METERS