A trolley of mass 4kg moving on a smooth horizontal platform with a speed of 1.0ms^-1 collides perfectly with a stationary trolley of the same mass on the same platform. Calculate the total momentum of the two trolleys immediately after the collision.

• A. 0.5Ns
• B. 1.0Ns
• C. 4.0Ns
• D. 8.0Ns

A sonometer wire under a tension of N10N, produces a frequency of 250Hz when plucked. Keeping the length of the wire constant, the tension is adjusted to produce a new frequency of 350Hz. Calculate the new tension

• A. 39.2N
• B. 19.6N
• C. 14.2N
• D. 7.4N

The resultant of two forces 12N and 5N is 13N. What is the angle between the two forces?

• A) 0o
• B) 45o
• C) 90o
• D) 180o

Tyres are treaded to?

• A. increase weight of tyres
• B. increase friction
• C. increase its longetivity
• D. look good

The velocity ratio of an inclined plane, inclines at an angle \(\theta\) to the horizontal can be expressed as

• A. (sin \(\theta)^{-1}\)
• B. \(\sin \theta\)
• C. (cos \(\theta)^{-1}\)
• D. \(\cos \theta\)

In an A.C circuit, the ratio of r.m.s value to peak value of current is

• A) 2
• B) 1/2
• C) 1/√2
• D) √2

(a) Explain the terms reactance and impedance in an a.c circuit.

(b) A source of e.m.f. 240 v and frequency 50 Hz is connected to a resistor, an inductor and a capacitor in series. When the current in the capacitor is 10A, the potential difference across the resistor is 140V and that across the inductor is 50V. Draw the vector diagram of the potential difference across the inductor, the capacitor and the resistor.

Calculate the (i) potential difference across the capacitor; (ii) capacitance of the capacitor; (iii) inductance of the inductor.

A body of mass 4.2kg moving with velocity 10ms^-1 due east, hits a stationary body of mass 2.8kg. If they stick together after collision and move with velocity V due east, calculate the value of V

• A. 3ms^-1
• B. 6ms^-1
• C. 7ms^-1
• D. 15ms^-1

If a source of solid is moving, a stationary listener will hear a sound of different frequency. This is called?

• A. doppler effect
• B. resonance
• C. ultra sound
• D. rarefaction

What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolution per seconds?

• A. 80Hz
• B. 600Hz
• C. 800Hz
• D. 1600Hz