(a)

When a positively charged conductor is placed near a candle flame, the flame spreads out as shown in the diagram below. Explain this observation.

(b) A proton moving with a speed of 5.0 x 10\(^{5}\) ms\(^{-1}\) enters a magnetic field of flux density 0.2 T at an angle of 30° to the field. Calculate the magnitude of the magnetic fcrce exerted on the proton. [Proton charge = 1.6 x 10\(^{-19}\) C]

(c)

The diagram below illustrates a 9.0 V battery of internal resistance 0.5 \(\Omega\) connected to two resistors of values 2.0 \(\Omega\) and R \(\Omega\). A\(_1\) A\(_2\) and A\(_3\) are ammeters of negligible internal resistances. If Al reads 4.0 A, calculate the:

(i) equivalent resistance of the combined resistors 2.0 \(\Omega\) and R \(\Omega\);

(ii) currents through A\(_1\) and A\(_3\) ; (iii) value of R.

The resultant of two forces is 50N. If the forces are perpendicular to each other and one of them makes an angle 0f 30^o with the resultant, find its magnitude.

• A. 100.0N
• B. 57.7N
• C. 43.3N
• D. 25.0N

A heat sensitive resistor made of a semiconductor is called?

• A. thermometer.
• B. thermostat.
• C. thermistor
• D. thermopile.

The secondary pigments consist of?

• A. blue, green, and violet
• B. yellow, green, and magenta
• C. magenta, yellow, and cyan
• D. red, green, and blue

In an AC circuit, resonance occurs when the impedance of the circuit is:

• A. Zero
• B. Maximum
• C. Equal to the capacitive reactance of the circuit
• D. Minimum

One of the features of the fission process is that

• A. its products are not radioactive
• B. it leads to chain reaction
• C. neutrons are not released
• D. the sum of the masses of the reactants equals the sum of masses of the products

An object moves with uniform speed round a circle. Its acceleration has

• A. constant magnitude and constant direction
• B. constant magnitude and varying direction
• C. varying magnitude but constant direction
• D. varying magnitude and varying direction

A hydraulic press has a large circular piston of radius 0.8m and a circular plunger of radius 0.2m. A force of 500N is exerted by the plunger. Find the force exerted on the piston

• A. 8000N
• B. 4000N
• C. 2000N
• D. 31N

In a Daniel cell, the depolarizer, positive and negative electrodes are respectively

• A. copper sulphate, copper and zinc
• B. manganese dioxide, carbon and zinc
• C. sulphuric acid, lead oxide and lead
• D. potassium hydroxide, nickel and iron.

A quantity which requires magnitude and direction to be specified is

• A. Temperature
• B. Distance
• C. Displacement
• D. Mass