Question

If you were to measure your pulse rate while in a spaceship moving away from the Sun at a speed close to the speed of light, you would find that it was

1. Much faster than normal
2. Much slower than normal
3. The same as it was here on Earth

Particles carrying the strong forces are

1. Photons
2. Gluons
3. Z or W bosons
4. None of the above

Which was the best particle discovered which is still today believed to be elementary, i.e. not made up of further constituents?

1. Electron
2. Gluon
3. Proton
4. photon

What is the purpose with the moderator water in a fission reactor?

1. protects the uranium fuel against air
2. slows down neutrons to thermal velocities
3. absorbs the released energy
4. transports the released energy out from the reactor

Why do we have decay with α emission but not with proton emission.

1. the proton is too light
2. the proton has too small charge
3. the α-is loosely bound
4. the α-particle has high binding energy per nucleon

The flow of charge per unit time defines

1. power.
2. current.
3. voltage.
4. resistance

A positively charged particle traveling with a velocity ‘v’ in an electric field ‘E’ experiences a force ‘F’ that must be

1. parallel to v
2. parallel to E
3. perpendicular to v
4. perpendicular to E

Phenomenon when a charged body attracts an uncharged body is called

1. Electromagnetic induction
2. Electrostatic induction
3. Charge movement
4. Electric current

Field that acts on object with mass is

1. Electric field
2. Gravitational field
3. Magnetic field
4. Force fields

Electric force on a dust particle having charge equal to 8X10^-19 C when plates are separated by a distance of 2cm and have a potential difference of 5 kV is

1. 2.0 X 10^-13 N
2. 3 N
3. 5 N
4. 20 N

.A candle 8 cm high is 40 cm in front of a mirror whose focal length is -70 cm. What is the height of the image?

1. 50 cm
2. 5 cm
3. 5 m
4. 5 km

Answer 1

Answers:

The same as it was here on earth ( Since, time measured from space ship,

T = T₀ / [1 - v² / c² ], take v = c , we get ,    T = T₀ )

Gluons

Photon

Slows down neutrons to thermal velocities

the α - particle has high binding energy per nucleon

current

parallel to E

Electrostatic Induction

Gravitational field

2.0 x 10^-13 N ,    ( since,      q = 8 x 10 ^-19C,   d = 2 cm = 2 x 10 ^{- 2}m,    V = 5 kV = 5 x 10 ³ V

we have,   E = F / q = V / d (or)    F = q V / d = 8 x 10 ^-19 x 5 x 10 ³/ 2 x 10 ^{- 2} = 2.0 x 10^-13 N )

5 cm ,     ( Since, 1/f = 1/u + 1/v     when, f = - 70 cm , u = 40 cm      we get   v = 25.45 cm ,   and

Let the hights are,     O = 8 c m,   I = ? ,       magnification,   m = v / u = I / O       or

I = O v / u = 5.09 cm ,     is the Image hight )