Hey, good to see you again. Here are the solutions to your questions: Physics What is the dimension of momentum? Step 1: Recall the formula for momentum. Momentum ($p$) is defined as the product of mass ($m$) and velocity ($v$). $$p = mv$$ Step 2: Determine the dimensions of mass and velocity. The dimension of mass is M. The dimension of velocity is length (L) divided by time (T), which is LT⁻¹. Step 3: Combine the dimensions. $$[p] = [m] \times [v] = \text{M} \times \text{LT}^{-1} = \text{MLT}^{-1}$$ The final answer is $\boxed{\text{a) MLT}^{-1}}$. A device which is made up of two or more plane mirrors is: A kaleidoscope uses multiple plane mirrors arranged to create symmetrical patterns through repeated reflection. The final answer is $\boxed{\text{a) Kaleidoscope}}$. What converts mechanical to electrical energy? A generator is a device that converts mechanical energy into electrical energy. Both DC generators and AC generators perform this function. The final answer is $\boxed{\text{C. DC generator}}$. The unit of specific heat capacity is: Step 1: Recall the formula for specific heat capacity ($c$). $$c = \frac{Q}{m \Delta T}$$ where $Q$ is heat energy, $m$ is mass, and $\Delta T$ is the change in temperature. Step 2: Substitute the units for each quantity. The unit for heat energy ($Q$) is Joules (J). The unit for mass ($m$) is kilograms (kg). The unit for change in temperature ($\Delta T$) is degrees Celsius (°C). Step 3: Combine the units. $$[c] = \frac{\text{J}}{\text{kg} \cdot \text{°C}} = \text{J/kg°C}$$ The final answer is $\boxed{\text{b) J/kg°C}}$. The device used to convert A.C to D.C is: A rectifier is an electrical device that converts alternating current (AC) to direct current (DC) by allowing current to flow in only one direction. The final answer is $\boxed{\text{b) Rectifier}}$. Dew point is the temperature at which: The dew point is the temperature to which air must be cooled to become saturated with water vapor, at which point condensation begins to form dew. The final answer is $\boxed{\text{b) Air becomes saturated}}$. Heat transfer in liquids mainly occurs by: Convection is the primary mode of heat transfer in liquids and gases, involving the movement of fluid particles from warmer to cooler regions, carrying heat with them. The final answer is $\boxed{\text{c) Convection}}$. Half-life is the time taken for: In radioactivity, half-life is the time required for half of the atomic nuclei of a radioactive sample to decay. The final answer is $\boxed{\text{b) Half of a radioactive substance to decay}}$. Biology Evolution is best defined as: Evolution refers to the gradual change in the heritable characteristics of biological populations over successive generations. The final answer is $\boxed{\text{b) Gradual change in organisms over time}}$. A food web is: A food web illustrates the complex network of feeding relationships between different organisms in an ecosystem, showing how multiple food chains are interconnected. The final answer is $\boxed{\text{b) Interconnection of many food chains}}$. The major supporting system in plants is: Xylem tissue, with its lignified cell walls, provides significant structural support to plants, especially in woody stems, helping them stand upright against gravity. The final answer is $\boxed{\text{a) Xylem}}$. Which of these is NOT a kingdom? In modern biological classification, Bacteria is recognized as a Domain, which is a taxonomic rank higher than a Kingdom. Plantae, Animalia, and Fungi are all Kingdoms. The final answer is $\boxed{\text{d) Bacteriae}}$. The largest game reserve in Nigeria is: Gashaka-Gumti National Park is the largest national park in Nigeria, encompassing a vast area of diverse ecosystems. The final answer is $\boxed{\text{d) Gashaka-Gumti National Park}}$. Anaerobic respiration occurs: Anaerobic respiration is a metabolic process that occurs in the absence of oxygen, where organisms break down glucose to produce energy. The final answer is $\boxed{\text{b) Without oxygen}}$. The membrane surrounding a vacuole is called: The tonoplast is the single membrane that encloses the vacuole in a plant cell, regulating the movement of ions and other substances into and out of the vacuole. The final answer is $\boxed{\text{b) Tonoplast}}$. Chemistry Ammonium sulphate is commonly used as: Ammonium sulphate ($(\text{NH}_4)_2\text{SO}_4$) is a widely used inorganic salt that serves as a nitrogen and sulfur fertilizer in agriculture. The final answer is $\boxed{\text{b) Fertilizer}}$. During electrolysis, the cathode is the electrode where: During electrolysis, the cathode is the negative electrode where reduction occurs, meaning species gain electrons. The final answer is $\boxed{\text{b) Reduction occurs}}$. Which of these is used to test for nitrogen dioxide (NO₂)? Nitrogen dioxide ($\text{NO}_2$) is an oxidizing gas. Acidified potassium iodide solution is used to test for oxidizing gases; $\text{NO}_2$ will oxidize iodide ions ($\text{I}^-$)