How will you charge a ballpoint pen refill by the method of friction ?
Take a used ballpen refill and rub it vigorously with a piece of polythene.
How will you charge a plastic comb (plastic scale or plastic pen) by the method of friction?
How will you charge an inflated rubber balloon by the method of friction ?
An inflated rubber balloon is rubbed with a woollen cloth whereas a ballpoint pen refill is rubbed with a polythene bag. Which of these will get positively charged?
A. Inflated rubber balloon B. Woollen cloth C. Ballpoint pen refill D. Polythene bag
(a) A and B (b) B and C (c) A and D (d) B and D
You bought a pen and three refills for rupees 25 and your friend wbought 2 pens and a refill for rupees 25. Try to represent the solution as equations. Can you find the cost of a pen and a refill separately?
Which of the following are biodegradable and which non-biodegradable? Glass bottle, Paper, Ballpoint pen refill, Hay, DDT, Wheat, Cake, Wood, Polythene bag, Jute bag, Cotton cloth, Grass, Vegetable peels