In the series a.c circuit shown above, the p.d across the inductor is 8Vr.m.s and that across the resistor is 6Vr.m.s. The effective voltage is
- A. 2V
- B. 10V
- C. 14V
- D. 48V
In the diagram above, if the internal resistance of the cell is zero, the ration of the powers P1 and P2 dissipated by R1 and R2
- A. R2/R1
- B. R1/R2
- C. R1+R2/R1
- D. R1+R2/R2
In the circuit above, The potential across each capacitor is 100V. The total energy stored in the two capacitors is
- A. 3.0 x 104J
- B. 3.0 x 102J
- C. 2.5 x 10-2J
- D. 6.0 x 10-3J
In the circuit above, the ammeter reads a current of 5.0 A when R = 8Ω and reads 7.0A when R = 5Ω. The value of the unknown resistance X is
- A. 10.0Ω
- B. 7.5Ω
- C. 5.0Ω
- D. 2.5Ω
The diagram above shows a magnet X with its south pole moved along a soft – iron bar PQ in the direction shown. After some time, the poles at P and Q respectively are
- A. North - North
- B. North - South
- C. South - North
- D. South - South
The diagram above shows the prism arrangement in a
- A. binocular
- B. spectrometer
- C. periscope
- D. projector
The diagram above represents a transverse electromagnetic wave travelling with speed 3.0 x 108ms-1. What is the frequency of the wave.
- A. 3.0 x 107Hz
- B. 9.0 x 107Hz
- C. 1.0 x 109Hz
- D. 3.0 x 109Hz
In the J-tube above, Y and X are on the same horizontal level and 30cm3 of air is trapped above Y when the atmospheric pressure is 75cm Hg, calculate the volume of air trapped above Y when 15cm Hg is now poured into the limb above X
- A. 15 cm3
- B. 25 cm3
- C. 35 cm3
- D. 45 cm3
The diagram above shows a lift pump with valves at P and Q. During a downward stroke of the piston
- A. both valves are open
- B. P is open while Q is closed
- C. P is closed while Q is open
- D. Both valves are closed
The diagram above shows a solid figure with base PQ and center of gravity G on a inclined plane. Which of the following statements is correct
- A. The solid will fall over if the vertical line through G lies outside the base
- B. The solid will fall over if the vertical line through lies inside the base
- C. The solid will not fall over if the vertical line through G lies outside the base
- D. The solid can never fall over
The figure above represents a frictionless pulley system in which a weight W is in equilibrium with a weight of 40N. Find the value of W
- A. 13.3N
- B. 20.0N
- C. 40.0N
- D. 80.0N
The diagram above shows the velocity-time graph of a vehicle. Its acceleration and retardation respectively are
- A. 8.0 ms-2, 4,0 ms-2
- B. 4.0 ms-2, 8.0 ms-2
- C. 4.0 ms-2, 2.0 ms-2
- D. 2.0 ms-2, 4.0 ms-2
If ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Pa is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
- A. ∆x ∆Px ≥ h
- B. ∆x ∆Px = 0
- C. ∆x ∆Px < h
- D. ∆x ∆Px = ∞
if ∆x is the uncertainty in the measurement of the position of a particle along the x-axis and ∆Px is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as
- A. ∆x ∆Px ≥ h
- B. ∆x ∆Px = 0
- C. ∆x ∆Px < h
- D. ∆x ∆Px = ∞
A semiconductor diode is used in rectifying alternating current into direct current mainly because it
- A. allows current to flow in either direction
- B. is non-linear
- C. offers a high input resistance
- D. allows current to flow only in one direction
2311Na + Proton → pqX + alpha particle
What are the values of p and q respectively in the equation above?
- A. 10 and 20
- B. 12 and 24
- C. 20 and 10
- D. 24 and 12
In the Rutherford scattering experiment, a beam of alpha particles was fired at a thin gold film with some of the particles being considerably deflected. This shows that
- A. a gold nucleus contains protons, neutrons and electrons uniformly distributed in a tiny volume
- B. the gold nucleus is positively charged and is concentrated in a tiny volume
- C. the gold nucleus emitted alpha particles
- D. the gold nucleus is concentrated in a tiny volume and contains alpha particles
in a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively, what is the voltage across the capacitor?
- A. 30V
- B. 40V
- C. 50V
- D. 70V
What is the speed of a particle of mass 10-27kg whose wavelength is 10-8m.
[h = 6.63 x 10-34Js]
- A. 6.63ms-1
- B. 66.30ms-1
- C. 663.00ms-1
- D. 6630.00ms-1
Gamma rays are produced when
- A. high velocity electrons are abruptly stopped in metals
- B. energy changes occur within the nucleus of atoms
- C. energy changes occur within the electronic structure of atoms
- D. electrons are deflected in very strong magnetic fields
The core of an efficient transformer should consist of laminated pieces of metal in order to
- A. increase the heat produced by increasing the eddy current
- B. increase the heat produced by reducing the eddy current
- C. reduce the heat produced by increasing the eddy current
- D. reduce the heat produced by reducing the eddy current