A wire of length 100 cm has a resistance of 10\(\Omega\). If its cross-sectional area is 0.005cm2, determine its resistivity
- A. 0.0005\(\Omega\)cm
- B. 0.0015\(\Omega\)cm
- C. 0.0016\(\Omega\)cm
- D. 0.0700\(\Omega\)cm
In the circuit diagram above, E is a battery of negligible internal resistance. If its emf is 9.0V. Calculate the current in the circuit “
- A. 1.8A
- B. 1.0A
- C. 0.8A
- D. 0.3A
Two identical charges situated 20cm apart in vacuum repel each other with a force of 1.0N.Calculate the value of each other with a force of 1.0N. Calculate the value of each charge. [(14 \(\pi \varepsilon_o)^{-1}\) = 9 x 109Nm2C-2]
- A. 21\(\mu C\)
- B. 3.6\(\mu C\)
- C. 4.0\(\mu C\)
- D. 4.4\(\mu C\)
A 15 \(\mu F\) capacitor is connected to a 240V, 50Hz ac. source. Calculate the reactance of the capacitance [\(\pi = 3.142\)]
- A. 16\(\Omega\)
- B. 68\(\Omega\)
- C. 106\(\Omega\)
- D. 212\(\Omega\)
An electric motor converts
- A. electrical energy to mechanical energy
- B. mechanical energy to electrical energy
- C. mechanical energy to chemical energy
- D. electrical energy to thermal energy
Which of the following conditions occur at resonance in a series RLC circuit? i. Impedance equals resistance ii. Current is maximum iii. Reactance is maximum iv. Current and voltage are 90° out of phase
- A. i and ii only
- B. i and ii only
- C. i, ii and iii only
- D. i, ii, iii and iv
The energy stored in a simple cell is
- A. electrical
- B. nuclear
- C. thermal
- D. chemical
In an ac circuit when the supply voltage frequency is equal to the resonant frequency, the current
- A. leads the supply voltge by 90o
- B. lags behind the supply voltage by 90o
- C. leads the supply voltage by 45o
- D. is in phase with the supply voltage
The region around a magnet in which magnetic force can be expressed is known as
- A. declination
- B. flux density
- C. field
- D. flux
An ammeter can be adapted to measure potential difference by using a
- A. shunt
- B. multiplier
- C. rheostat
- D. resistance box
An object is placed in front of two plane mirrors inclined at 60o to each other. Determine the number of the images formed
- A. 2
- B. 3
- C. 5
- D. 7
an observer hears an echo 1.26 seconds after blowing a whistle near a cliff. calculate the distance of the observer from the cliff. [speed of sound in air = 330ms-1]
- A. 104.4m
- B. 207.9m
- C. 415.8m
- D. 523.8m
A fish inside a pond appears to be at a depth of 1.5m when viewed vertically from above. The refractive index of the water in the pound is 1.3. Calculate the apparent displacement of the fish
- A. 2.50m
- B. 1.95m
- C. 1.50m
- D. 0.45m
The diagram above illustrates an electromagnetic wave travelling with speed 3.0 x 108ms-1. Calculate the wave length of the wave
- A. 0.05m
- B. 0.15m
- C. 0.16m
- D. 0.40m
The functional difference between a lens and a mirror is that a lens
- A. reflects a beam of light while a mirror refracts it
- B. refracts a beam of light while a mirror reflects it
- C. absorbs incident rays while a mirror transmit them
- D. transmits incidents ray whle a mirror absorbs them
Which of the following relations about the focal length fo of the objective and focal length fe of the eye piece of a compound is correct?
- A. fo = fe
- B. fo < fe
- C. fo > fe
- D. fe = 2fo
Refraction of lights differs from reflection in that, in refraction i. at least two media are involved ii. there is a change in the direction of the ray iii. the speed of the ray changes. Which of the statements above is/are correct?
- A. i only
- B. i ad ii only
- C. ii and iii only
- D. i and iii only
A transverse wave can be distinguished from a longitudinal wave by
- A. diffraction
- B. relection
- C. refraction
- D. polarization
The quality of a note depends on its
- A. frequency
- B. pitch
- C. overtones
- D. amplitude
A car traveling at 30ms\(^{-1}\) overcomes a frictional resistance of 100N while moving. Calculate the power developed by the engine. [1 hp = 0.75 kW]
- A. 0.23hp
- B. 0.40hp
- C. 4.00hp
- D. 4.40hp
The mass of an empty density bottle is 30g. When filled with a liquid, the mass of the bottle and the liquid is 40g. On heating the filled bottle through 40ºc, the mass reduces to 38g. Calculate the apparent cubic expansivity of the liquid
- A. 6.25 x 10K-1
- B. 6.25 x 10-3K-1
- C. 2.50 x 10-3K-1
- D. 2.50 x 10-4K-1