Explanation: A digital storage oscilloscope makes use of a conventional cathode ray tube. As a result, the cost is reduced.

Explanation: A bridge circuit makes use of a comparison measurement method. In this method the bridge compares the value of an unknown component with a standard value of a given component.

Explanation: Kelvin’s double bridge method is used for measurement of Low Resistance, Anderson Bridge is not used for measurement of Resistance, and Direct-Deflection method is used for Measurement of High Resistance.

Explanation: A vibration galvanometer is used for detecting the balance condition. The oscillator is used as a source of the supply voltage. The tuned detector is the most sensitive detector for a single frequency value.

Explanation: At balance condition, no current flows through the headphones present in the AC bridge circuit. As a result the detector indicates null deflection at balance condition.

Explanation: Tuned circuit is used for detecting balance condition. Vibration galvanometer is used for the same purpose. Unknown value of capacitance is obtained by comparing it with a standard value.

where, R2, R3 and R4 are the known non-inductive resistances.

Explanation: In an inductance comparison bridge, the resistance R2 and R3 are variable. The value of resistance R2 is varied so as to control the inductance of the bridge.

Explanation: A Schering bridge can be used with both low voltage as well as high voltages. A Schering bridge is basically used for the measurement of small capacitances at low voltages with high precision.

Explanation: In a high voltage Schering bridge, the balance equation does not depend on the frequency of operation of the circuit. A detector is only used for detecting the balance condition in a bridge circuit.

Explanation: The series combination of R and C in a Wagner earth device forms a potential divider across the ratio arms. It is also known as the guard arm.

Explanation: For measuring Capacitance De-Sauty’s Bridge and Schering Bridge should be used. For measuring Frequency Wien’s Bridge is used. For measuring Mutual Inductance Heaviside and Campbell’s Bridge are used.

Explanation: A multiplier is basically a non-inductive, high resistance that is used to extend the range of a D.C. voltmeter. Multiplier consists of a low range D.C. voltmeter connected in series with it.

Explanation: Using cylinders made of Bakelite, the windings of a C.T. are wound over one another. This setup is mounted on a steel tank sheet filled with transformer oil.

Explanation: As the voltage ratio changes, the frequency also changes. It depends on the relative value of the core loss component Io as well as the leakage reactance. The effects due to the voltage ratio and the change in frequency oppose each other.

Explanation: When the secondary burden of a potential transformer increases, it leads to an increase in the secondary current. As a result the primary current also increases.

Explanation: A.C. circuits make use of power factor of the circuit in addition to the current flowing through the circuit and the voltage across the circuit. As a result, a wattmeter is used to measure A.C. power.

Explanation: In a Dynamometer type wattmeter, when the moving coil deflects the pointer moves over the scale. The pointer then comes back to rest at a point where the deflecting torque equals the controlling torque.

Explanation: For lagging power factor of the load, the wattmeter reading is more. As a result, the wattmeter shows a reading opposite to that of the inductance.