Physics Past Questions and Answers

(a) State the three characteristics of sound and the factor on which each of them depends.<br/>(b) Explain resonance as applied to sound.<br/>(c) What role does echo play in the construction of a concert hall?<br/>(d) The surface of an ear drum (assumed circular) has a radius 2.1 mm. It resonates with an amplitude of 0.8 x 10\(^{-7}\) in as a result of impulses received from an external body vibrating at 2400 Hz. If the resulting pressure change on the ear drum is 3.6 x 10\(^{-5}\) NM\(^{-2}\), calculate the:<br/>(i) period of oscillation;<br/>(ii) velocity;<br/>(iii) acceleration;<br/>(iv) force. [\(\pi\) = 3.14 ].

(a) Define electromotive force.<br/>(b) State:<br/>(i) the principle of operation of a potentiometer,<br/>(ii) two advantages that a potentiometer has over a voltmeter in measuring potential difference.<br/>(c)(i) Sketch and label a diagram of a gold-leaf electroscope.<br/>(ii) Give one use of a gold-leaf electroscope.<br/>(d)(i) Explain the action of a magnetic relay.<br/>(ii) List two factors which determine the magnitude of an induced emf in a coil.<br/>(iii) A current of 5 A passes through a straight wire in a uniform magnetic field of flux density 2.0 x10\(^{-3}\) T. Calculate the force per unit length exerted on the wire when it is inclined at 30° to the field.

Which of the following statements about mass and weight are correct? i. Weight is the force of gravity on a body. ii. The mass of a body is the quantity of matter in the body. iii. The weight of a body is greatest at the equator. iv. The mass of a body is greatest at the poles

Which of the following statements about mass and weight are correct? i. Weight is the force of gravity on a body. ii. The mass of a body is the quantity of matter in the body. iii. The weight of a body is greatest at the equator. iv. The mass of a body is greatest at the poles

Materials that can be stretched and still return to their original forms when the stresses are removed are said be