### A potential difference of 6V is used to produce a current of 5A for 200s through a heating coil. The heat produced is

Jamb 1978 A potential difference of 6V is used to produce a current of 5A for 200s through a heating coil. The heat produced is  A. 4800 cal  B. 6000 cal  C. 2400 J  D. 240 kcal  E. 6000J ANSWER: Option E EXPLANATION: Just apply the equation below; heat produced […]

### A calorimeter of thermal capacity 80j contains 20g of water at 25°C. Water at 100°C is added so…

JAMB 1980 A calorimeter of thermal capacity 80j contains 20g of water at 25°C. Water at 100°C is added so that the final temperature of the set-ups is 50°C. The amount of water added is (Heat capacity of water = 4.18J/g/°C) A. 20g B. 25g C. 45g D. 50g E. […]

### The statements below were made by some students describing what happened during the determination of the melting point of solids

Jamb 1978 The statements below were made by some students describing what happened during the determination of the melting point of solids.  1. The temperature of the solid was constant until melting started.  2. The temperature of the solid rose until melting started  3. During melting, the temperature was rising  […]

### A 500kg car which was initially at rest travelled with an acceleration of 5m/s², its kinetic energy after 4 seconds was

Jamb 1979 A 500kg car which was initially at rest travelled with an acceleration of 5m/s², its kinetic energy after 4 seconds was A. 10⁵J B. 2.5 x 10³J, C. 2 x 10³J D. 5 x 10³J E. 5 x 10⁵J  ANSWER: Option A EXPLANATION:  KE = ½mv² Since v […]

### An object is positioned between two plane mirrors inclined at right angles to each other. The object is 1 unit distance from each mirror. The number of images formed is

Jamb 1978 An object is positioned between two plane mirrors inclined at right angles to each other. The object is 1 unit distance from each mirror. The number of images formed is A. 1 B. 2 C. 3 D. 4 E. 5 ANSWER: Option C EXPLANATION: Use the equation below […]

### Heat is supplied to a block of ice 0° until half of it has melted…

JAMB 1980 Heat is supplied to a block of ice 0° until half of it has melted. Which of the following statements is true? A. the temperature rises and the ice exoands B. the temperature remains constant and the volume of ice decreases C. the ice gives out heat as […]

### High Tension(H.T.) transmission means

JAMB 1980 High Tension(H.T.) transmission means A. to transmit a given amount of power, the tension in the conducting wire must be high B. heat is not lost when current is passed through a conductor C. heat is gained when a given power is transmitted D. a big transformer is […]