The current in the primary coil of a transformer is 2.5A. If the coil has 50 turns and the secondary 250 turns, calculate the current in the secondary coil. Neglect energy losses in the transformer

• A. 0.2A
• B. 0.5A
• C. 2.5A
• D. 5A

A plane inclined at an angle at 30° to the horizontal has an efficiency of 50%. The force parallel to the plane required to push a load of 120 N uniformly up the plane is

• A. 40N
• B. 60N
• C. 120N
• D. 200N

Boyle’s law may be Written as

• A. P1V1= P2V2
• B. V1 = V2 ÷ T1T2
• C. P1T1 = P2T2
• D. P1V1 ÷ T1 = P1V1 ÷ T2

If the refractive index of crown glass is 1.51, its critical angel is.

• A) 48.6°
• B) 22.5°
• C) 41.5°
• D) 45.0°

Three capacitors of capacitance 2μF, 4μFand 8μF are connected in parallel and a P.D of 6V is maintained across each capacitor, the total energy stored is

• A) 2.52 x 10^-6J
• B) 6.90 x 10^-6J
• C) 2.52 x 10^-4J
• D) 6.90 x 10^-4J

A football is kicked at an angle of 45° to the horizontal over a defense line up with a velocity of 15\(ms^{-1}\). Calculate the magnitudeof horizontal velocity of the ball at its highest point [Neglect friction, g = 10\(ms^{-2}\)].

• A. 0.0\(ms^{-1}\)
• B. 5.6\(ms^{-1}\)
• C. 10.6\(ms^{-1}\)
• D. 15.0\(ms^{-1}\)

An object of mass 0.40 kg attached to the end of a string is whirled around in a horizontal circle of radius 2.0m with a constant speed of 8\(ms^{-1}\). Calculate the angular velocity of the object

• A. 0.8rad\(s^{-1}\)
• B. 2 rad\(s^{-1}\)
• C. 4 rad\(s^{-1}\)
• D. 8 rad\(s^{-1}\)

A wire of 5Ω resistance is drawn out so that its new length is two times the original length. If the resistivity of the wire remains the same and the cross-sectional area is halved, the new resistance is

• A. 40Ω
• B. 20Ω
• C. 10Ω
• D. 5Ω

(a) Explain the statement the capacitance of a capacitor is 5\(\mu\)F.

(b)(i) State the factors upon which the capacitance of a parallel plate capacitor depend.

(ii) State how the capacitance depends on each of these factors stated in (b)(i).

(c) A series arrangement of three capacitors of values 8uF, 12\(\mu\)F, and 24\(\mu\)F is connected in series with 90-V battery.

(i) Draw an open-circuit diagram for this arrangement.

(ii) Calculate the effective capacitance in the circuit.

(iii) On closed circuit, calculate the charge on each capacitor when fully charged.

(iv) Determine the p.d across the 8\(\mu\)F capacitor.

A 400 N box is being pushed across a level floor at a constant speed by a force P of 100 N at an angle of 30.0° to the horizontal, as shown in the the diagram below. What is the coefficient of kinetic friction between the box and the floor?

• A. 0.19
• B. 0.24
• C. 0.40
• D. 0.22