Question Library

Which of the following materials is a good insulator?

Three cells each of emf, 1.0 V, and internal resistance, 2 \(\Omega\), are connected in parallel across a 3\(\Omega\) resistor. Determine the current in the resistor.

One major reason why electrical appliances in homes are normally earthed is that the-----------

Which of the following is not a consequence of hydrogen bubbles covering the copper plate of a primary cell?

A cell whose internal resistance is 0.55\(\Omega\) delivers a current of 4 A to an external resistor. The lost voltage of the cell is?

Which of the following liquid is a poor conductor of electricity?

Which of the current-voltage characteristics shown above is that exhibited an ohmic conductor?

The electrochemical equivalent of silver is 0.0012g/C. If 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5mins, the current must be?

The resistance of a 40W car head lamp, drawing current from a 12V battery is ____.

You are provided with an ammeter, a resistor, key, metre bridge, and other necessary apparatus. i. Connect a circuit as shown in the diagram above. ii. Close the key and use the jockey to make contact with AB at N such that AN = d = 25cm iii. Read and record the ammeter reading. iv. Evaluate 1\(^{-1}\). v. Repeat the procedures for values of d = 35cmm, 50cm, 65cm and 80cm. In each case, record I and determine 1\(^{-1}\) vi. Tabulate your results. vii. Plot a graph with log on the vertical axis and d on the horizontal axis. viii. Determine the slope, s of the graph. ix. State two precautions taken to obtain accurate results. (b)i. Use your graph to determine the value of d = l = 1.5A. ii. State two factors that affect the resistance of a wire.

The symbol illustrated above is that of a resistor?

In an electrolysis experiment, the ammeter records a steady current of 1 A. The mass of copper deposited in 30 minutes is 0.66 g. Calculate the error in the ammeter reading. [Electrochemical equivalent of copper = 0.00033 g C\(^{-1}\)]

A 12\(\Omega\) resistor dissipates 8kJ of heat in 20s. Calculate the current through the resistor

In a discharge tube, most of the gas is pumped out so that electricity is conducted at?

A cell of e.m.f 12V and internal resistance 4Ω is connected to an external resistor of resistance 2Ω. Find the current flow.