Q1. Which of the following cannot be charged easily by friction?
👆 Click the correct option:
✅ Answer
(b) A copper rod
📝 Explanation
Metals like copper are good conductors ⚙️, so any charge produced by rubbing flows away quickly through the rod (and into our hand or surroundings). That’s why a copper rod does not hold static charge easily.
🤓 Did You Know
If metal could hold static charge easily, you’d get tiny shocks all day from keys 🔑, door handles 🚪, and coins 🪙 (more than we already do 😄).
Q2. When a glass rod is rubbed with a piece of silk cloth the rod
👆 Click the correct option:
✅ Answer
(b) becomes positively charged while the cloth has a negative charge.
📝 Explanation
When glass is rubbed with silk, electrons move from the glass rod to the silk cloth.
So:
• Glass rod loses electrons ➕ becomes positively charged
• Silk gains electrons ➖ becomes negatively charged
🤓 Did You Know
This is one of the most famous “static electricity” experiments in science labs 🔬. Glass + silk is like a classic combo, just like chai + biscuit ☕🍪.
Q3. Write T against true and F against false in the following statements.
(a) Like charges attract each other (T/F)
(b) A charged glass rod attract a charged plastic straw (T/F)
(c) Lightning conductor cannot protect a building from lightning (T/F)
(d) Earthquakes can be predicted in advance (T/F)
✅ Answer
(a) F
(b) T
(c) F
(d) F
📝 Explanation
(a) Like charges repel, not attract ↔️
(b) Glass rod is usually positive and plastic straw is usually negative (if rubbed), so unlike charges attract ❤️
(c) Lightning conductors do protect buildings by safely sending charge to the Earth 🌍
(d) Earthquakes cannot be predicted accurately in advance ❌
🤓 Did You Know
Nature follows a simple rule: “Same vibes push away, opposite vibes pull closer.” 😄⚡
Q4. Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.
✅ Answer
When we pull off a sweater, friction between the sweater and body causes static charges. These charges get discharged suddenly, producing a crackling sound.
📝 Explanation
In winters ❄️, air is dry, so charges don’t leak away easily. Rubbing creates static electricity ⚡, and when the charge suddenly jumps (discharges), we hear that “crack-crack” sound 🔊.
🤓 Did You Know
That tiny crackling is like mini lightning in your clothes 😅⚡ (very small, but same idea!).
Q5. Explain why a charged body loses its charge if we touch it with our hand.
✅ Answer
When we touch a charged body, the charge is transferred to the Earth through our body. This process is called earthing, and the body becomes discharged.
📝 Explanation
Our body is a good conductor because it contains water and salts 💧🧂. So when we touch a charged object, charge flows through us into the Earth 🌍, and the object becomes neutral.
🤓 Did You Know
That’s why touching a metal object first can reduce static shocks in winters 😄🖐️.
Q6. Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?
✅ Answer
• Scale → Richter scale
• Yes, a seismograph can record an earthquake of magnitude 3.
• But such an earthquake is mild and does not cause much damage.
📝 Explanation
The Richter scale measures earthquake magnitude 📈. A magnitude 3 earthquake is small and may be felt slightly, but usually it does not damage buildings. Seismographs are sensitive instruments, so they can record it easily 🖊️📊.
🤓 Did You Know
Richter scale is not “1 to 10 fixed.” Big earthquakes can go above 9 too 😮🌍.
Q7. Suggest three measures to protect ourselves from lightning.
✅ Answer
1. Stay indoors in a safe building 🏠 or inside a closed vehicle 🚗.
2. Avoid open fields, tall trees 🌳, poles, and metal objects ⚙️.
3. Do not use wired telephones or touch electrical appliances during a thunderstorm.
📝 Explanation
Lightning looks for the easiest path to the ground 🌩️. Tall objects and metal conduct electricity well, so staying away from them reduces risk. Indoors or inside a vehicle is safest.
🤓 Did You Know
A car is safe because the metal body acts like a shield (Faraday cage) 🚘⚡.
Q8. Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon.
✅ Answer
• Two charged balloons have like charges → they repel each other.
• A charged balloon and an uncharged balloon → the uncharged one gets induced opposite charge, so they attract each other.
📝 Explanation
• If both balloons have the same type of charge (like +/+ or -/-), they push away ↔️
• If one balloon is uncharged, charges inside it shift due to induction, making the nearer side oppositely charged, so attraction happens ❤️
🤓 Did You Know
That’s why a rubbed balloon can stick to a wall 🧱🎈 like magic (but it’s science 😄).
Q9. Describe with the help of a diagram an instrument which can be used to detect a charged body.
✅ Answer
The instrument is an Electroscope.
• It consists of a metal rod 📎, with two strips of aluminium foil 🪙🪙 inside a jar.
• When a charged object touches the rod, both strips get the same charge and repel each other.
• This shows the body is charged.
👉 (Here, a simple diagram of an electroscope should be drawn by students: Jam bottle + cardboard lid + paperclip + foil strips).
📝 Explanation
An electroscope works on the principle: like charges repel ↔️. When charge reaches the leaves (foil strips), both get the same charge, so they spread apart. The more they spread, the stronger the charge can be.
🤓 Did You Know
Early scientists used gold leaves in electroscopes because gold is super thin and light ✨🪙.
Q10. List three states in India where earthquakes are more likely to strike.
✅ Answer
1. Jammu & Kashmir
2. Gujarat (Rann of Kutch)
3. Assam / North-East states
📝 Explanation
These regions lie near plate boundaries or fault zones 🪨. Tectonic movement is more active there, so earthquakes occur more frequently.
🤓 Did You Know
The Himalayas are still growing slowly because plates are pushing each other ⛰️😮.
Q11. Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?
✅ Answer
• Move to an open space 🌾, away from buildings, trees, and electric poles.
• Squat low 🧎 on the ground, protect your head.
• Do not run towards buildings or take shelter under tall structures.
📝 Explanation
During earthquakes, the biggest danger outside is falling objects: glass, bricks, electric wires, and poles ⚠️. Open ground is safest. Protecting the head reduces injury risk.
🤓 Did You Know
Most injuries in earthquakes happen due to falling objects, not because the ground “opens up” like in movies 🎬😄.
Q12. The weather department has predicted that a thunderstorm is likely to occur on a certain day. Suppose you have to go out on that day. Would you carry an umbrella? Explain.
✅ Answer
❌ No, I would not carry an umbrella.
👉 Because carrying an umbrella (with a pointed metallic rod) during a thunderstorm increases the chance of being struck by lightning ⚡.
📝 Explanation
Umbrellas can have metal parts and also make you a taller point in open areas ☔⚡. Lightning tends to strike higher and sharp points more easily, so carrying an umbrella in a thunderstorm is risky.
🤓 Did You Know
If you’re stuck outside, the safest move is to find a building or a car, not a tree 🌳❌🚗✅.