An electric water pump rate 1.5 kW, lifts 200kg of water through a vertical height of 6 meters in 10 seconds. What is the efficiency of the pump? [g = 10ms-2, neglecting air resistance]

• A. 90.0%
• B. 85.0%
• C. 80.0%
• D. 65.0%

The function of the magnanese (IV) oxide in a leclanche cell is to

• A. decrease the e.m.f. of the cell
• B. prevent local action in the cell
• C. prevent polarization in the cell
• D. increase the density of the electrolyte

In storing magnets, keepers are used to

• A. reduced self-demagnetization
• B. cancel the effect of the earth's magnetic field
• C. protect the magnet from stray electric field
• D. increase the strangth of the magnets

An object is projected with a velocity of 100 ms^-1 from the ground level at an angle 0 to the vertical. If the total time of flight of the projectile is 10 s, calculate ?. (g = 10 ms^-2).

• A. 0°
• B. 30°
• C. 45°
• D. 60°

The property of wave shown in the diagram below is?

• A. Diffraction
• B. Refraction
• C. Polarisation
• D. Interference

A bar of initial length /₀ is heated through a temperature change \(\Delta\)t to a new length I. The linear expansivity, a, of the bar is

• A. \(\frac{/ - /_o}{/ \Delta t}\)
• B. \(\frac{/ - /_o}{/_o \Delta t}\)
• C. /_o(1 + \(\Delta\) t)
• D. \(\frac{/ - /_o}{/(1 + \Delta t)}\)

Which of the following instruments is used to measure relative humidity?

• A. Hydrometer
• B. Barometer
• C. Manometer
• D. Hygrometer

Which of the following obeys Ohm's law?

• A. all metals
• B. diode only
• C. all electrolytes
• D. glass

Which of the following cases cannot produce total internal reflection? A light ray travelling from

• A. glass to water
• B. kerosene to air
• C. air to water
• D. water to ice

Which of the following are produced after a nuclear fusion process? i. one heavy nucleus. ii. neutrons^-1. iii. protons. iv. Energy.

• A. i and ii
• B. i and iv
• C. ii and iii
• D. ii and iv