### A string is sustaining a stationary wave when

Jamb 1978 A string is sustaining a stationary wave when A. the frequency of the wave is hot proportional to the wavelength of the wave B. the amplitude of vibration is always zero C. two equal waves are travelling in opposite directions D. the waves are longitudinal E. the frequency […]

### A magnet is moved through a coil of wire. The e.m.f. produced in the wire depends on

Jamb 1978 A magnet is moved through a coil of wire. The e.m.f. produced in the wire depends on  A. the number of turns in the coil  B. the strength of the magnet  C. the speed at which the magnet is moved  D. all of the above  E. none of […]

### The motion of the moving skin of a talking drum can rightly be described as

JAMB 1980 The motion of the moving skin of a talking drum can rightly be described as A. translational B. random C. rotational D. oscillatory E. transitory Correct Answer: Option D Explain your answer in the comment box below and let’s have a discussion so as to have a great […]

### Which of the following statements on the use of X-rays is incorrect? X-rays are used

JAMB 1980 Which of the following statements on the use of X-rays is incorrect? X-rays are used A. in hospitals to obtain photogaphs of tissues and bones in the body B. for the treatment of malignant growths like cancer cells C. in detecting fingerprints D. to reveal hidden flaws in […]

### The total capacitance of the circuit above is

JAMB 1980 The total capacitance of the circuit above is? A. 0.25mF B. 0.50mF C. 0.75mF D. 1.25mF E. 1.50mF Correct Answer: Option E Explanation  CTotal in parallel = C1 + C2 + C3  CTotal = 2 + 2 + 2 → 6 1/CT = 1 / C1 + 1 […]

### A piece of rubber 10cm long stretches 6mm when a load of 100N is hung from it. What is the strain

Jamb 1978 A piece of rubber 10cm long stretches 6mm when a load of 100N is hung from it. What is the strain? ANSWER: Option C EXPLANATION: Using the equation  Strain = ∆L/L Where; ∆L —> change in length               L —> Original Length If L1 is the original length and […]

### The relative densities of zinc, brass, copper, gold and silver are respectively 7.1, 8.5, 8.9, 19.3…

JAMB 1980 The relative densities of zinc, brass, copper, gold and silver are respectively 7.1, 8.5, 8.9, 19.3, 10.5. A metal ornament which weighs 0.425kg and can displace 50 x 10^-6m³ of water is made of A. zinc B. brass C. copper D. gold E. silver Correct Answer: Option B […]

### Which of the following is true for the image formed by a convex mirror

Jamb 1978 Which of the following is true for the image formed by a convex mirror? 1. The image is always virtual II. The image is always erect II. The image lies between pole and focus IV. The image is never magnified V. The focal length is negative A. I […]

### The temperature of 20°C is the same as

Jamb 1978 The temperature of 20°C is the same as  A. 36°F B. 68°F C. 11.1°F D. 43.1°F E. 25°F ANSWER: Option  B EXPLANATION: First thing you should know is the lower and upper fixed point of both Fahrenheit and Celsius scale. For Fahrenheit: upper is 212°F while lower is […]

### Which of the following does NOT cause a reduction of the surface tension of water

JAMB 1980 which of the following does NOT cause a reduction of the surface tension of water? A. soap solution B. detergent C. alcohol D. camphor E. grease Correct Answer: Option E Explain your answer in the comment box below and let’s have a discussion so as to have a […]