advguruji.blogspot.com

Electricity - Extra questions Q1. Find the heat generated in a wire of resistance 100Ω connected to a constant voltage supply of 80 volts for 15 seconds. Q2. An electric iron of rating 200V, 4A is connected to a suitable 200V voltage source. If a fan with power consumption 100W is connected to the iron with an independent switch. Calculate - (i) Current for the entire circuit. (ii) Resistance of the entire circuit. Q3. Find the resistivity of a wire with resistance 200Ω, length 2 m and having cross-sectional area 2.5 mm². Q4. Which has more resistivity : a thin copper wire at 30°C or a thick copper wire at 30°C? Q5. Which has more resistivity : a copper wire at 30°C or an aluminium wire at 30°C? Q6. Which has more resistivity : a copper wire at 30°C or a copper wire at 42°C with same length and diameter? Q7. Calculate the resistance of a wire with resistivity 2 × 10-⁶ Ωm, length 5 m and diameter 2 mm. Take, π = 3.14 Q8. How many 10 Ohms resistors are required to make an equivale

Multiple Choice Questions Q1. The removal of Hydrogen from a substance is known as ---- (i) oxidation (ii) dehydration (iii) reduction (iv) crystallisation Q2. The development of unpleasant smell and taste in fat and oil containing foods due to aerial oxidation is ---- (i) acidity (ii) rancidity (iii) displacement (iv) sublimation Q3. In order to obtain a yellow precipitate from Lead Nitrate , you should mix a solution of ---- (i) Potassium Chloride (ii) Potassium Iodide (iii) Potassium Bromide (iv) Potassium Cyanide Q4. In exothermic reactions ---- (i) thermostat is required (ii) energy is released (iii) Energy is absorbed (iv) None of the above Q5. Find a & b in - (i) a = 1, b = 1 (ii) a = 1, b = 2 (iii) a = 3, b = 1 (iv) a = 2, b = 1 Q6. Which gas/gases are released when FeSO 4 is heated? (i) Sulphur Dioxide (ii) Sulphur Trioxide (iii) Both (i) & (ii) (iv) None of these Q7. Which compound is used in black and white photography? (i) Silver Chloride (ii) Sil