UNICAL Physics 2020/2021 Past Questions

Practice each question, then open it to see the full details.

Capacitors are used in the following devices, except

A.water pumping machines
B.ceiling fans
C.electric irons
D.television sets

The radius of a wheel is 30.0cm and that of its axle is 6.0cm. Calculate the effort required to lift a load of 120.0n using this machine, assuming 100% efficiency.

A.600.0N
B.40.0N
C.24.0N
D.20.0N

A girl stands on a scale in a lift. If the reading on the scale is less than her weight, then the lift is moving

A.upward at uniform speed.
B.upward with uniform acceleration.
C.downward with uniform speed.
D.downward with uniform acceleration.

A 12Ω resistor dissipates 8kJ of heat in 20s. Calculate the current through the resistor.

A.5.8A
B.6.9A
C.30.0A
D.33.3A

A 15µF capacitor is connected to a 240V, 50Hz a.c source. Calculate the reactance of the capacitor. [π = 3.142]

A.16Ω
B.68Ω
C.106Ω
D.212Ω

If electrons are accelerated from rest through a potential difference of 10 kV, what is the wavelength of the associated electron? [m = 9.1 × 10^-31kg e = 1.6 × 10^-19C, 6.6 × 10^-34Js ]

A.1.22 x 10^{-11^m}
B.3.87 x 10^{-10^m}
C.2.27 x 10^{11^m}
D.2.27 x 10^{14^m}

The ability of the human eye to focus objects on the retina is referred to as the power of

A.interference
B.diffraction
C.accomodation
D.superposition

A hydrometer is an instrument used in measuring

A.density of liquid
B.relative density of a liquid.
C.relative humidity of a liquid
D.vapour pressure of a fluid

The energy in the nucleus of atoms produce heat which can be used to generate

A.kinetic energy
B.mechanical energy
C.electrical energy
D.potential energy

Calculate the number of moles of an ideal gas of volume 12.0m³ at a pressure of 6 x 10³Nm^-2 and 275C [R=8.0Jmol^-1K^-1]

A.3.0
B.1.5
C.15.0
D.30.0