Which of the following graphs correctly represents the variation of mass of a given material deposited with time for constant current in Faraday’s Law of Electrolysis?
- A. A
- B. B
- C. C
- D. D
What is the angle of dip at the magnetic equator
- A. \( 45^{\circ} \)
- B. \( 0^{\circ} \)
- C. \( 90^{\circ} \)
- D. \( 180^{\circ} \)
A bread toaster uses a current of 4A when plugged in a 240V line. it takes 1 minute to toast slices of bread. what is the energy consumed by the toaster
- A. 5.76 x 104J
- B. 1.60 x 104J
- C. 3.60 x 103J
- D. 1.60 x 102J
Find the frequencies of the first three harmonics of a piano string of length 1.5m, if the velocity of the wave on the string is 120ms-1
- A. 40Hz, 80Hz, 120Hz
- B. 80Hz, 160Hz, 240Hz
- C. 180Hz, 360Hz, 540Hz
- D. 369Hz, 180Hz, 90Hz
In the diagram above, determine the r.m.s current
- A. 31A
- B. 48A
- C. 60A
- D. 80A
In the circuit diagram above , the ammeter reads a current of 3A when R is 5Ω and 6A when R is 2Ω. Determine the value of x
- A. 8Ω
- B. 2Ω
- C. 10Ω
- D. 4Ω
The diagram above shows a closed side 0.5m in a uniform electric field E in the direction shown by the arrows. What is the flux Φ for the box?
- A. 0.5 E
- B. 2.0 E
- C. 0.2 E
- D. 0.0 E
The diagram above shows the capacitors C1, C2 and C3 2μF, 6μF and 3μF respectively. The potential difference across C1, C2 and C3 respectively are
- A. 4V, 6V and 2V
- B. 2V, 6V and 4V
- C. 6V, 4V and 2V
- D. 6V, 2V and 4V
The diagram above shows two capacitors P and Q of capacitance 2μF and 4μF respectively connected to a d.c source. The ratio of energy stored in P to Q is
- A. 4:1
- B. 2:1
- C. 1:4
- D. 1:2
In the diagram above , the current I is
- A. 3/8
- B. 9/11
- C. 11/9
- D. 8/3
If ray travelling in air is incident on a transparent medium as shown in the diagram, the refractive index of the medium is given as
- A. cosα / sinβ
- B. sinα / sinβ
- C. cosβ / sinα
- D. sinβ / sinα
The diagram above is a block and tackle pulley system in which an effort of 80N is use to lift a load of 240N. The efficiency of the machine is
- A. 60%
- B. 50%
- C. 40%
- D. 33%
In the diagram above, which of the simple pendula will resonate with P when set into oscillation
- A. T
- B. U
- C. R and T
- D. Q and R
The magnetic force on a charged particle moving with velocity v is
- A. proportional to both the magnitude of the charge and the velocity v
- B. independent of the magnitude of the charge
- C. proportional to the velocity v only
- D. proportional to the magnitude of the charge only
A capacitor of 20 x 10-12F and an inductor are joined in series. The value of the inductance that will give the circuit a resonance frequency of 200kHz is
- A. I/16 H
- B. I/8 H
- C. I/64 H
- D. I/32 H
Energy losses through eddy currents are reduced by using
- A. low resistance wires
- B. insulated soft iron wires
- C. few turns of wires
- D. high resistance wires
A transistor function mainly as a
- A. switch and amplifier
- B. rectifier and an amplifier
- C. charge storer and an amplifier
- D. charge storer and a switch
The force on a current carrying conductor in a magnetic field is greatest when the
- A. conductor makes an angle of 60° with the field
- B. force is independent of the angles between the fields and the conductor
- C. conductor is parallel with the field
- D. conductor is at right angle with the field
At reasonance, the phase angle in an a.c. circuit is
- A. 90°
- B. 60°
- C. 0°
- D. 180°
The process of energy production in the sun is
- A. nuclear fission
- B. nuclear fussion
- C. electron collision
- D. radioactive decay
Which of the following metals will provide the greatest shield against ionizing radiation
- A. Iron
- B. Manganese
- C. Alminium
- D. Lead