General Knowledge Quiz (Previous Years) for NDA & Other Defence Exams: 3rd April

Dear Students, Defence Adda is providing you all with this quiz on General Knowledge questions for NDA & Other Defence Exams.

Q1. The thermal capacity of a substance is 5 cal/°F. What is water equivalent of the substance?
(a) 5g
(b) 9g
(c) 25/9 g
(d) 5kg

Q2. Which of the following properties are most desirable for a cooking pot?
(a) High specific heat capacity and low conductivity
(b) Low specific heat capacity and high conductivity
(c) High specific heat capacity and high conductivity
(d) Low specific heat capacity and low conductivity

Q3. A Centigrade thermometer and Fahrenheit thermometer are dipped in boiling water. The temperature of water is lowered till the Fahrenheit thermometer registers half of its upper fixed point. What is the corresponding fall temperature registered by the Centigrade thermometer?
(a) Half of its range of temperature between the upper and the lower fixed points
(b) Approximately 41°C
(c) Approximately 59°C
(d) 18°C

Q4. Which zone of a candle flame is the hottest?
(a) Dark innermost zone
(b) Outermost zone
(c) Middle luminous zone
(d) Central zone

Q5. Two spheres of the same metal have radii in the ratio 1: 2. Their heat capacities are in what ratio?
(a) 1: 2
(b) 1: 8
(c) 2: 1
(d) 1: 4

Q6. Two equal amounts of water are mixed by gently pouring both into an insulated cup. One part is initially at 90°C, and the other part is initially at Ti °C. If the final temperature of the mixture is 131°C, what is the value of T?
(a) 90°
(b) 68
(c) 20
(d) 0

Q7. Why do two ice blocks join to form one block when pressed together?
(a) Melting point of ice increases with increase in pressure
(b) Melting point of ice is lowered with increase in pressure
(c) Melting point of ice remains unchanged with increase in pressure
(d) Melting point of ice is 0°C

Q8. Evening Sun is not as hot as the mid-day sun. What is the reason?
(a) In the evening, radiation travel slowly
(b) In the evening, the temperature of the sun decreases
(c) Ozone in atmosphere absorbs more light in the evening
(d) In the evening, radiations travel larger distance through atmosphere

Q9. When water is heated from 0°C to 20°C, how does its volume change?
(a) It shall increase
(b) It shall decrease
(c) It shall first increase and then decrease
(d) It shall first decrease and then increase

Q10. A solid is melted (above the melting point) and allowed to cool down at normal condition. It variation of temperature as a function of times is as shown in the figure given below. What is the reason for the plateau (Flat position) in the central region of the cooling curve as shown in the figure?

(a) Latent heat of fusion of the solid
(b) Specific heat of the solid
(c) Thermal conductivity of the solid
(d) Thermal capacity of the solid.

S1. Ans.(a)
Sol. Water equivalent of a substance is the amount of water that would absorb the same amount of heat as the substance per degree rise in temperature. The heat capacity and water equivalent both are equal to the product of the mass of a substance and specific heat.

S2. Ans.(b)
Sol. Low specific heat capacity and high conductivity is the most desirable for a cooking pot.

S3. Ans.(b)

S4. Ans.(b)
Sol. Due to complete combustion, the outer zone is blue in color. This zone is the hottest in temperature when compared to the other zones. This blue colored zone is the non-luminous part of the flame.

S6. Ans.(d)

S7. Ans.(b)
Sol. Melting point of ice decreases with increase in pressure.

S8. Ans.(d)
Sol. In evening, the radiations from the sun travel larger distance through atmosphere that’s why evening sun is not as hot as the mid-day sun.

S9. Ans.(d)
Sol. Water contracts from 0°C to 4°C, hence its volume decreases and after 4°C the volume increases.

S10. Ans.(a)