Physics Past Questions and Answers

A body whose initial velocity is u is uniformly accelerated to a final velocity v in t seconds. If the distance travelled is s, and the acceleration is a, which equation is INCORRECT for the motion of the body?

A S = ut+\(\frac{1}{2}\)at²
B V² = u² + 2as
C V =u + at
D V = u + 2as
E S = \(\frac{1}{2}\)(u+v)t

Question 77:

Which material is best for making a permanent magnet?

A Aluminium
B Cobalt
C Copper
D Soft iron
E Steel

Question 78:

A cell can supply currents of 0.60 A and 0.30 A through a 2.0 ω and a 5.0 ω resistor respectively. What is the internal resistance of the cell?

A 0.2 ω
B 0.4 ω
C 1.0 ω
D 3.0 ω
E 9.0 ω

Question 79:

Which statement is a correct consequence of the uncertainly principle?

A A particle’s kinetic energy cannot be measured accurately at any time
B Both momemtum and energy of a particle can be known with absolute certainly
C It is possible to measure exactly both the position and momentum of a particle at the same time
D The complete knowledge of the position of a particle implies the complete ignorance of its energy
E The uncertainty in our knowledge of energy and the duration taken to measure it, are each less than Planck’s constant.

Question 80:

Which statements(s) is/are NOT true?

I. A saturated vapour is one that is in equilibrium with its liquid in a closed space. II. A vapour contains molecules with varying kinetic energy and their distances apart are smaller than those of the molecules of a liquid
III. Relative Humidity = \(\frac{\text{Saturated vapour pressure at dew point}} {\text{Saturated vapour pressure at air temperature}}\) x 100%

IV. The saturated vapour pressure of water increases with temperature

A I only
B II only
C II and III only
D III and IV only
E II, III and IV only