2018 - JAMB Physics Past Questions and Answers - page 5
choose the option that best completes the gaps. All God’s prophets were given the great…
Commission means a task or mission to accomplish.
Take note of the double ‘s’ and the double ‘m’. All other options are wrongly spelt
The inner diameter of a small test tube can be measured accurately using a
A vernier scale is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation; thereby increasing resolution and reducing measurement
A pulley system has three pulleys in the fixed block and two in the movable block and if the pulley has an efficiency of 72%, the mechanical advantage of the system is?
Mechanical Advantage, M.A Velocity Ration (V.R) × Efficiency
Hence,M.A = 5 × 0.72
M.A = 3.6
When an atom loses or gain a charge it becomes
When an atom gains or loses an electron it becomes an ion. If atom that gains a negative electron, it becomes a negative ion but if it loses an electron it becomes a positive ion
A ball of mass 800g moving horizontally with a speed of 5m/s hits a vertical wall and rebounds with the same speed. The impulse experienced by the ball is?
Initial momentum = (0.8) × (5)
= 4.0kgms\(^{-1}\)
Final momentum
= (0.8) × (– 5)
= – 4.0kgms\(^{-1}\)
Impulse on ball
= Change in momentum
= 4.0 – (– 4.0)
= 8.0.0kgms\(^{-1}\)
The force between the molecules of a liquid in contact with that of a solid is?
Cohesion is the inter-molecular attractive force acting between two adjacent portions of a substance, particularly of a solid or liquid. It is this force that holds a piece of matter together
A body of mass 100g moving with a velocity if 10ms-1 collides with a wall. If after collision it moves with a velocity of 2.0ms−1 in the opposite direction, calculate the change in momentum.
Momentum = Mass x Velocity
Change in Momentum = Mass x (change in velocity)
Change in Momentum = Mass x (v - u)
Mass = 100g = 0.1kg
U = 2ms\(^{-1}\)
V = 10ms\(^{-1}\)
Change in momentum = m (v − u)
= 0.1 (10 − 2)
= 0.1 (8)
= 0.8Ns
A 20kg mass is to be pulled up a slope inclined at 300 to the horizontal. If efficiency of the plane is 75%. The force required to pull the load up the plane is J [g=10ms\(^{− 2}\)]
V. R = \(\frac{1}{Sinθ}\)
m = 20kg
V.R = \(\frac{1}{Sin 30 }\)
= 2
Efficiency = 75%
Load = mg
= 20 x 10 = 200N
Efficiency = \(\frac{M.A}{V.R \times 100}\)
75/100 = \(\frac{M.A}{2}\)
M .A = 75 x \(\frac{2}{100}\)
M. A = 1.5
Since M. A. = \(\frac{\text{Force}}{\text{Load}}\)
Force = 1.5 x 200
= 87 N
The tendency of a body to remain at rest when a force is applied to it is called.
Inertia is the property of a body by virtue of which it opposes any agency that attempts to put it in motion or, if it is moving, to change the magnitude or direction of its velocity. Inertia is a passive property and does not enable a body to do anything except oppose such active agents as forces and torques. A moving body keeps moving not because of its inertia but only because of the absence of a force to slow it down, change its course, or speed it up.
An object is placed 20cm from a concave mirror of focal length 10cm. The linear magnification of the image produced is?
\(\frac{I}{V}\) = \(\frac{1}{f}\) – \(\frac{1}{u}\)
\(\frac{I}{V}\) = \(\frac{1}{10}\) – \(\frac{1}{20}\)
= \(\frac{1}{20}\) V
V = 20cm.
M = \(\frac{V}{U}\)
= \(\frac{20}{20}\)
= 1