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Ajụjụ 2 Ripọtì
Of two identical tuning forks with natural frequency 256Hz, one is loaded so that 4 beats per second are heard when they are sounded together. What is the frequency of the loaded tuning fork?
Akọwa Nkọwa
Beat = F2 - F1
4 = F2 - 256
F2 = 260Hz
Ajụjụ 3 Ripọtì
A given mass of an ideal gas occupies a volume V at a temperature T and under a pressure p. If the pressure is increased to 2p and the temperature reduced to 12T , then the percentage change in the volume of the gas is
Akọwa Nkọwa
P2V2T2 = P1V1T1
P2 = 2P1
T1 = 2T2
2P1V2T2 = P1V12T1
V2 --V1
% change = V1−14V1V1 X 100%
= 75%
Ajụjụ 4 Ripọtì
A gun of mass 2.0kg fires a bullet of mass 16 x 10 -2kg due East. If the bullet leaves the nozzle of the gun with a velocity of 150ms-1, what is the recoil velocity of the gun?
Akọwa Nkọwa
Gun momentum = bullet momentum
2 x v = 1.6 x 10-2 x 150
v = 1.2ms-1 in opposite direction
Ajụjụ 5 Ripọtì
For a concave mirror to form a teal diminished image, the object must be placed
Ajụjụ 6 Ripọtì
Which of the following statements is (are) NOT correct? i. pressure changes do not affect the speed of sound in air ii. the velocity of sound increases with temperature iii. the quality of the note depends only on its frequency
Akọwa Nkọwa
Ajụjụ 7 Ripọtì
Which of the following statements about the compound microscope and astronomical telescope is (are) correct? i. the final image of a compound microscope is located at infinity ii. the final image of the astronomical telescope is always erect iii. the objective lens of a compound microscope has a very short focal length
Akọwa Nkọwa
Ajụjụ 8 Ripọtì
Which of the following statements is (are) NOT true about the emission of the photoelectrons from metallic surfaces? i. all metallic surfaces emits the same number of photoelectrons in a given light ii. most metallic surfaces emit the same number of photoelectrons in visible and infra-red light iii. a metallic surface emits photoelectrons only if the frequency of the incident light is higher than its own characteristics threshold frequency
Ajụjụ 10 Ripọtì
Which of the following is a correct explanation of the inertia of a body?
Ajụjụ 12 Ripọtì
Which of the following i. β -particles ii. protons iii. neutrons iv. α -particles. may be found in light nuclei?
Ajụjụ 13 Ripọtì
What volume of alcohol with a density of 8.4 x 102kgm-3 will have the same mass as 4.2m3of petrol whose density is 7.2 x 102kgm-3?
Akọwa Nkọwa
Mass = Density x Volume
4.2 x 7.2 x 102 = v x 8.4 x 102
= 3.6m3
Ajụjụ 14 Ripọtì
A short bar magnet is placed in earth's magnetic field, as shown above, which of the points II and III are/is possible positions of a neutral point?
Ajụjụ 16 Ripọtì
In the circuit Shown above, calculate the effective capacitance between X and Y
Akọwa Nkọwa
Ajụjụ 17 Ripọtì
If a solid changes directly into a gas when heat is applied the process is called
Akọwa Nkọwa
Ajụjụ 19 Ripọtì
A small steel needle is carefully floated on water in a beaker. When a few drops of kerosine are introduced into the water the needle sink. Which of the following statements correctly explain(s) the observation? i. there is tension on the water surface ii. kerosine reduces the density of water so that needle becomes denser than water iii. kerosine reduces the surface tension of water
Akọwa Nkọwa
Ajụjụ 22 Ripọtì
Heat is supplied uniformly at the rate of 100W to 1.0 x 10-2kg of a liquid for 20 seconds. If the temperature of the liquid rises by 5oC, then the specific heat capacity of the liquid is
Akọwa Nkọwa
Heat energy = Electrical energy
mcθ = power x time
5 x 1 x 10-2 x C = 100 x 20
C = 4.0 x 104Jkg-1k-1
Ajụjụ 23 Ripọtì
The spectrum of white light consists of coloured lights arranged in the following order
Ajụjụ 24 Ripọtì
The distance travelled by a particle starting from rest is plotted against the square of the time elapsed from the commencement of motion. The resulting graph is linear, the slope of this graph is a measure of
Akọwa Nkọwa
Ajụjụ 26 Ripọtì
Which of the following properties of matter CANNOT be utilized for temperature measurement? The
Akọwa Nkọwa
Ajụjụ 27 Ripọtì
Which of the following statements describes an atom accurately? i. atoms of all elements are identical ii. an atom contains a nucleus and number of electrons iii. due to the electrons in the atom an atom is negatively charged iv. electrons in the atom move in circular orbits round the nucleus
Ajụjụ 28 Ripọtì
Two cells each of e.m.f. 1.5V and an internal resistance 2? are connected in parallel. Calculate the current flowing when the cells are connected to a 1? resistor
Akọwa Nkọwa
E = 1.5v
rT = 2×22+2
= 1
e.m.f. = I(R + r)
1.5 = I(1 + 1)
I = 0.75Ω
Ajụjụ 29 Ripọtì
Radio waves have a velocity of 3 x 108ms-1. A radio station sends out a broadcast on a frequency of 800kHz. The wavelength of the broadcast is
Akọwa Nkọwa
v = Fλ
3 x 108 = λ x 800 x 103
λ = 375.0m
Ajụjụ 30 Ripọtì
A force varying linearly with the distance acts on a body as shown above, The work done on the body by the force during the first 10m of motion is
Ajụjụ 31 Ripọtì
A body of mass 5kg initially at rest is acted upon by two mutually perpendicular forces 12N and 5N as shown in fig.3. If the particle moves in the direction QA, calculate the magnitude of the acceleration
Akọwa Nkọwa
R = ?122+52
R = 13N and R = F = ma
13 = 5 x a
= 2.60ms-2
Ajụjụ 32 Ripọtì
If a water pump at Kainji Dam is capable of lifting 1000kg of water through a vertical height of 10m in 10s, the power of the pump is [g = 10ms-2]
Akọwa Nkọwa
power = work donetime
= 1000×10×1010
= 10kW
Ajụjụ 33 Ripọtì
The electromotive force obtained from a simple dynamo may be increased by
Akọwa Nkọwa
Ajụjụ 35 Ripọtì
What is the cost of running five 50W lamps and four 100W lamps for 10 hours if electrical energy costs 2 kobo per kWh?
Akọwa Nkọwa
PT = (5 x 50) + (100 x 4)
= 650watts
Energy(kWhr) = 650 x 10-3 x 10
= 6.5 kWhr
1kWhr cost 2 kobo ; 6.5 kWhr will cost 2×6.51
= 13 kobo
Ajụjụ 36 Ripọtì
A simple pendulum, 0.6m long, has a period of 1.5s. What is the period of a similar pendulum of 0.4m length in the same location?
Ajụjụ 37 Ripọtì
The lower and upper fixed points marked on a mecury-in-glass thermometer are 210mm apart. The end of the mercury column in the tube is 49mm above the lower fixed point in a room. What is the temperature of the room in degrees Celsius?
Akọwa Nkọwa
210mm .... 100oC
49mm .... θ
0mm .... 0oC
49−0210−0 = θ−0100−0
49210 = θ100
θ = 23.3oC
Ajụjụ 38 Ripọtì
For which of the underlisted quantities is the derived unit ML2T2 correct? i. momentum of a force ii. work iii. acceleration
Akọwa Nkọwa
Moment = force x distance
= m x a x d
= kg x ms2 x m1
= ML2T2
Ajụjụ 39 Ripọtì
A coin is placed at the bottom of a cube of glass tern thick. If the refractive index of the glass is ? , how high does the coin appear to be raised to an observer looking perpendicularly into the glass?
Akọwa Nkọwa
Let apparent depth = X
μ = tx ⇒ X = tu
raised of coin = t - x
= t - tμ
= t(μ−I)μ
Ajụjụ 40 Ripọtì
When vibration occurs in air column, the distance between a node and an antinode is equal to
Akọwa Nkọwa
Ajụjụ 42 Ripọtì
A galvanometer of resistance 5.0W has full-scale deflection for a current of 100mA. How would its range be extended to 1.0A? By placing a resistance of
Ajụjụ 43 Ripọtì
All the heat generated in a 5Ω resistor by 2A flowing for 30 seconds is used to evaporate 5g of a liquid at its boiling point. Which of the following is the correct value of the specific latent heat of the liquid?
Akọwa Nkọwa
Heat energy = electrical energy
mL = I2Rt
5 x L = 2 x 2 x 5 x 30
L = 120Jg-1
Ajụjụ 45 Ripọtì
A plane inclined at an angle of 30o to the horizontal has an efficiency of 60%. The force parallel to the plane required to push a load of 120N uniformly up the plane is
Akọwa Nkọwa
V.R = 1sin30 = 2
Efficiency = m.AV.R x 100%
60 = 120effort x 12 x 100
Effort = 100N
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