2016: In a dry cell (battery), which of the following are used as electrolytes?

(a) Ammonium chloride and Zinc chloride

(b) Sodium chloride and Calcium chloride

(c) Magnesium chloride and Zinc chloride

(d) Ammonium chloride and Calcium chloride
2017: Sound waves travel at 300 m/s. Sound produced at a point is heard by a person after 5 seconds while the same sound is heard by another person after 6 seconds. What could be the maximum and minimum distances between the two persons?

(a) 1.8 km, 0.15 km

(b) 2.2 km, 0.20 km

(c) 2.8 km, 0.25 km

(d) 3.3 km 0.3 km
2018: Consider the following pairs : National Cities Highway Connected

1. NH 4: Chennai and Hyderabad
2. NH 6: Mumbai and Kolkata
3. NH 15: Ahmedabad and Jodhpur

Which of the above pairs is/are correctly matched?

(a) 1 and 2 only
(b) 3 only
(c) 1, 2 and 3
(d) None
2019: Superconductors are so called because they

(a) Efficiently conduct heat from one hot body to another

(b) Offer no resistance to conduction of heat at high temperatures

(c) Offer no resistance to conduction of electricity at low temperatures

(d) Produce high temperatures while conducting electricity
2020: Living organisms require at least 27 elements of which 15 are metals. Among these, those required in major quantities include

(a) Potassium, Manganese, Molybdenum & Calcium
(b) Potassium, Molybdenum, Copper & Calcium
(c) Potassium, Sodium, Magnesium & Calcium
(d) Sodium, Magnesium, Copper & Manganese