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 machine whose efficiency is 75% is used to lift a load of 1000N. Calculate the effort put in to the machine if it has a Velocity ratio of 4.

• A. 343.32N
• B. 233.33N
• C. 333.33N
• D. 334.33N

The equation P^aV^bT^c= constant reduces to Charles Law if

• A. a=1, b=1and c=0
• B. a=1, b=0 and c=-1
• C. a=0, b=1 and c=1
• D. a=0, b=1 and c=-1

Body floats in fluid when its …………………

• A. Displaces its own volume of the liquid (fluid)
• B. Displaces its own weight of the fluid
• C. Displace its own density of the fluid
• D. Is no longer subjected to gravity

Plane waves through a narrow gap emerge as circular waves. This phenomenon is known as

• A. interference
• B. dispersion
• C. refraction
• D. diffraction

A body of mass 5kg falls from a height of 10m above the ground. What is the kinetic energy of the body just before it strikes the ground? (Neglect energy losses and take gravity as 10ms^-2)

• A. 5J
• B. 25J
• C. 250J
• D. 500J

An object 0 lies at a distance m in front of concave mirror of focal length f. If m< f, then the final image obtained will be

• A. virtual and diminished
• B. magnified and erect
• C. real and inverted
• D. diminished and erect

Two isotopes of uranium are designed as \(^{238}U\) and \(^{235}U\). The numbers 238 and 235 represent their

• A. atomic numbers
• B. nucleon numbers
• C. proton numbers
• D. neutron numbers

The area under a velocity-time graph represents

• A. speed
• B. acceleration
• C. moment
• D. distance

Calculate the energy of the third level of an atom if the ground state energy is - 24.8eV

• A. -9.20eV
• B. -8.20eV
• C. -2.75eV
• D. -1.75eV