To understand what the pointer of a shunt-type ohmmeter indicates when the test terminals are open, let's delve into the working principles of the ohmmeter.

An ohmmeter is an instrument used to measure electrical resistance. The basic working principle of an ohmmeter involves the flow of current through the resistance to be measured. The current flowing through the resistor results in a deflection of the meter's pointer, which corresponds to the resistance value.

1. Shunt-Type Ohmmeter: In a shunt-type ohmmeter, the meter movement is connected in parallel with the resistance being measured. When measuring resistance, the current flows from the battery through the resistor and the meter movement.
2. Open Test Terminals: If the test terminals are open, there is no complete circuit for the current to flow. Effectively, the resistance in this scenario is infinite because there is an open path and no current can flow through the circuit.
3. Pointer Indication: In the case of an open circuit, since the resistance is infinite, there is no current flowing through the meter. The ohmmeter is designed so that the pointer moves across a scale that reads from zero at one end (indicating a short circuit, or zero resistance) to infinity at the other end (indicating no circuit, or infinite resistance).

Based on the above analysis, when the test terminals of a shunt-type ohmmeter are open, the pointer will move towards the infinite resistance mark. The correct answer is Infinite resistance.

This can be reinforced by considering how the scale of an ohmmeter is calibrated. The infinite resistance condition corresponds to the maximum possible movement on the ohmmeter scale, confirming that the pointer indicates infinite resistance when the terminals are open.