UNIPORT Physics 2019/2020 Past Questions

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

An electric kettle with negligible heat capacity is rated at 2000W, if 2.0Kg of water is put in it, how long will take temperature of water to rise from 20° to 100°? [specific heat capacity of water = 4200JKg9.6ms^-1K^-1]

A.336s
B.240s
C.168s
D.84s.

A coil of copper wire of N turns is kept rotating between the poles of a permanent magnet such that the magnetic flux linking the coil changes continuously. Which of the following statements is TRUE?

A.An e.m.f. is induced in the coil such that when the change of flux is positive the e.m.f. is positive, and when the change of flux is negative, the e.m.f. is negative
B.An e.m.f. is induced in the coil whose magnitude is inversely proportional to both the number of turns in the coil and the rate of change of magnetic flux
C.An e.m.f. is set up in the permanent magnet which reduces the flux in the coil to zero
D.A current flows in the coil and an e.m.f. is set up proportional to both the rate of change of the flux and the number of turns.

The half-life of a radioactive element is 9 days. What fraction of atoms has decayed in 36 days .

A.1/16
B.1/4
C.1/2
D.15/16

Which of the following cannot be used to measure the temperature of a substance?

A.variation of pressure with temperature
B.expansivity of liquid
C.change in resistance of a conductor
D.change of colour with temperature

An object is placed 36cm from a convertible lents of focal length 24cm. If a real image, which is 4cm night, is formed, calculate the height of the object.

A.2.0cm
B.4.0cm
C.6.0cm
D.10.0cm

An object of weight 10N immersed in a liquid displaces a quantity of the liquid. If the liquid displaced weighs 6N, determine the upthrust on the object.

A.20N
B.10N
C.6N
D.4N

A ball is thrown vertically into the air with an initial velocity u. What is the greatest height reached?

A.u/2g
B.3u²/2g
C.u²/g
D.u²/2g
E.2u²/g

A radioactive substance has a half life of 4 years. If its activity today is 200 dps, its activity in 8 years from today is

A.50 dps
B.25 dps
C.20 dps
D.10 dps

A man walks 1 km due east and then 1 km due north. His displacement is

A.1 km N15°E
B.1 km N30°E
C.-√2 km N45°F
D.2 km N75°E

A ball is thrown up into the air. At the highest point of its trajectory the ball:

A.is accelerating downwards
B.has zero acceleration
C.is accelerating upwards
D.is still moving upwards