Calculate the upthrust on an object of volume 50cm3 which is immersed in liquid of density 103 kgm-3 [g = 10ms-2]

• A. 0.8N
• B. 2.5N
• C. 0.5N
• D. 1.0N

In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic center will

• A. pass through undeviated
• B. pass through the center of curvature after refraction
• C. emerge parallel to the principal axis
• D. pass through the principal focus after refraction

When compared with water, mercury is preferred as a thermometric liquid because

• A. has a higher density
• B. has lower specific heat capacity
• C. exhibits anomalous thermal expansion
• D. contains molecules which have very strong adhesive forces

A cell of e.m.f. 1.5V and internal resistance of 2.5Ω is connected in series with an ammeter of resistance 0.5W and a resistor of resistance of 7.0Ω. Calculate the current in the circuit.

• A. 0.15A
• B. 0.20A
• C. 2.10A
• D. 3A

A rectangular block of dimensions 2.0m x 1.0m x 0.5m weighs 200N. calculate the maximum pressure exerted by the block on a horizontal floor.

• A. 100Nm^-2
• B. 200Nm^-2
• C. 300Nm^-2
• D. 400Nm^-2

The graph above shows the relationship between sin i and sin r for a ray of light in air incident on a liquid surface. If i and r are respectively angles of incidence and refraction, deduce the refractive index of the liquid from the graph

• A. 1.63
• B. 1.50
• C. 1.33
• D. 1.25

The charge carriers in gasses are

• A. ions only
• B. electrons and ions
• C. electrons and holes
• D. electrons only

(a) State three conclusions that can be drawn from Rutherford's experiment on the scattering of alpha particles by a thin metal foil in relation to the structure of the atom

The diagram below illustrates th3 energy levels of an electron in an atom. If an excited electron moves from n\(_2\) to n\(_\theta\), calculate the:

(i) frequency;

(ii) wavelength of the emitted radiation. [ h = 6.6 x 10\(^{-34}\) Js; le V = .6 x 10\(^{-19}\) J; C = 3.0 x 10\(^8\) ms\(^{-1}\)]

(c) The following nuclear equations represent two types of radioactivity.

\(^{226}_{88}R_a \to ^{222}_{86}R_n + ^a_2a\) (Equation A)

\(^{14}_7N + ^4_2a \to ^{17}_8O + ^1_1p\) (Equation B)

Identify each type and explain briefly the difference between them

If a sonometer has a fundamental frequency of 450HZ, what is the frequency of the fifth overtone?

• A. 2700Hz
• B. 456Hz
• C. 444Hz
• D. 75Hz

A stream is flowing at 0.75m/s and a boat heading perpendicular for the stream landed at the opposite bank at an angle of 30°. Calculate the velocity of the boat.

• A. 1.50ms-1
• B. 1.00ms-1
• C. 0.86ms-1
• D. 0.65ms-1