In Fleming’s left hand rule middle finger indicates the direction of the
a.
electric current
Correct Answer
b.
induced electric current
c.
movement of the conductor
d.
magnetic field
Step-by-Step AI Explanation
Verified Method
According to Fleming's Left-Hand Rule, the thumb points in the direction of the force (motion), the index finger points in the direction of the magnetic field, and the middle finger points in the direction of the electric current. Therefore, (a) is correct. Induced current (b) is associated with Fleming's Right-Hand Rule.
Q2mcq1 mark
0.75 A current flows through an electric bulb when it is connected to a 220 V generator. Then the electric power of this bulb is
a.
125 W
b.
135 W
c.
165 W
Correct Answer
d.
195 W
Step-by-Step AI Explanation
Verified Method
The electric power is calculated using the formula $P = V \times I$. Given $V = 220 \text{ V}$ and $I = 0.75 \text{ A}$, then $P = 220 \times 0.75 = 165 \text{ W}$. Thus, option (c) is correct.
Q3mcq1 mark
If the number of turns in a current carrying circular coil is increased by 10 times, then the producing magnetic field increases by
a.
100 times
b.
10 times
Correct Answer
c.
20 times
d.
1000 times
Step-by-Step AI Explanation
Verified Method
The magnetic field produced by a current-carrying circular coil is directly proportional to the number of turns ($n$). Thus, if the number of turns is increased by 10 times, the magnetic field also increases by 10 times. Option (b) is correct.
Q4short answer1 mark
Draw the symbols of the following components used in an electric circuit.
i) Electric cell
ii) Rheostat or variable resistance.
Step-by-Step AI Explanation
Verified Method
i) Electric cell: A symbol consisting of two parallel vertical lines of unequal length, where the longer line represents the positive terminal (+) and the shorter, thicker line represents the negative terminal (-).
ii) Rheostat/Variable resistance: A symbol consisting of a resistor (a zigzag line) with an arrow pointing across it or a slider moving along the resistor.
Q5short answer1 mark
Glass prisms A, B and C are arranged as shown in the figure given below. When a ray of white light is passed through prism A, does the spectrum of light form on the screen ? Give reason.
Step-by-Step AI Explanation
Verified Method
No, a spectrum of light will not be seen on the screen. When white light passes through prism A, it splits into its component colors (dispersion). If prism B is placed in an inverted position relative to prism A, it recombines the dispersed colors back into a single beam of white light. Therefore, the light emerging from prism B is white light, and no spectrum is formed on the screen.
Q6short answer2 marks
State the laws of refraction of light.
Step-by-Step AI Explanation
Verified Method
The laws of refraction are:
1. The incident ray, the refracted ray, and the normal to the interface of two transparent media at the point of incidence all lie in the same plane.
2. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for a given pair of media (Snell's Law): $\frac{\sin i}{\sin r} = \text{constant}$.
Q7short answer2 marks
What precautions should be taken to avoid the overloading in domestic electric circuits ? Electrical appliances having metallic body are to be earthed essentially. Why ?
Step-by-Step AI Explanation
Verified Method
Precautions to avoid overloading:
1. Do not connect too many high-power appliances (e.g., fridge, AC, iron) to a single socket or circuit.
2. Ensure the circuit is protected by a proper fuse or circuit breaker (MCB).
Why earthing is essential:
Earthing is necessary to prevent electric shocks. If there is a leakage of current in an appliance with a metallic body, the current flows directly to the ground through the earth wire instead of passing through the body of the person using it, as the earth wire offers a path of very low resistance.
Q8short answer2 marks
Observe the given diagram and answer the questions given below :
i) Mention the direction of electric current flowing in the conductor.
Step-by-Step AI Explanation
Verified Method
The direction of the electric current is determined by the orientation of the magnetic field lines or the application of the Right-Hand Thumb Rule. If the thumb points in the direction of the current, the curled fingers indicate the direction of the magnetic field. Based on standard diagrams provided in textbooks for this question, the current flows in the direction indicated by the arrow on the conductor wire.
Q8long answer3 marks
An object 5 cm in size is placed at 30 cm in front of a concave mirror of focal length 20 cm. At what distance from the mirror should a screen be placed in order to get a sharp image ? Find the nature and size of the image formed.
Step-by-Step AI Explanation
Verified Method
Given: Object size ($h_o$) = 5 cm, Object distance ($u$) = -30 cm, Focal length ($f$) = -20 cm. Using mirror formula: $\frac{1}{f} = \frac{1}{v} + \frac{1}{u} \implies \frac{1}{-20} = \frac{1}{v} - \frac{1}{30}$. Solving gives $\frac{1}{v} = \frac{1}{30} - \frac{1}{20} = \frac{2-3}{60} = -\frac{1}{60}$. Thus, $v = -60$ cm. The screen should be placed 60 cm in front of the mirror. Magnification $m = \frac{h_i}{h_o} = -\frac{v}{u} = -\frac{-60}{-30} = -2$. Therefore, $h_i = -2 \times 5 = -10$ cm. The image is real, inverted, and 10 cm in size.
Q9short answer2 marks
Observe the given diagram and answer the questions given below :
ii) State the law that helped to determine the direction of current.
Step-by-Step AI Explanation
Verified Method
The law used to determine the direction of the induced current in a conductor moving in a magnetic field is Fleming's Right-Hand Rule.
🎉 10 Free Sample Solutions Completed
Unlock All 52 Questions & Solutions
Sign up free in seconds to unlock step-by-step AI answers for the remaining 42 questions.
Draw the ray diagram of the image formed when an object is kept between $F_1$ and $2F_1$ of a convex lens. Mention the nature and position of the image formed.
($F_1$ : Principal focus of the lens)
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
How do you trace the magnetic field lines formed around a bar magnet using compass needle ? Two magnetic field lines do not intersect each other. Why ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) i) What is 'Potential difference' ? ii) What are the advantages of connecting the electrical appliances in parallel in domestic electric circuits ? b) i) State Ohm's law. ii) What is 'electrical resistance' of a conductor ? On what factors does it depend ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
The electronic configuration of the three elements $P, Q$ and $R$ respectively are $2, 8, 2$; $2, 8$ and $2, 8, 7$. Among these, the elements that can react with each other to produce an ionic compound are
a.
$P$ and $Q$
b.
$P$ and $R$
c.
$Q$ and $R$
d.
$P, Q$ and $R$
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) What is near-sightedness (myopia) ? Mention the causes for this defect. b) What is power of accommodation of the eye ? What are the changes that occur in the eye while seeing the distant objects ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Observe the test tubes A, B and C given in the following figures. i) In which test tube the iron nail undergoes rust ? Why ? ii) Iron nails present in other two test tubes do not rust. Why ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Write the diagram to show the reaction of zinc granules with dilute sulphuric acid and testing hydrogen gas by burning. Label the following : i) Zinc granules ii) Hydrogen gas.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) How does the addition reaction of carbon compounds is different from substitution reaction ? Give an example for each. b) Name the carbon compounds having the following structural formula : i), ii), iii), iv).
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) Mention any two factors that help to determine that a change is a chemical reaction. b) Mention the type of chemical reaction that takes place when sodium sulphate solution is added to barium chloride solution. Write the balanced chemical equation for this reaction.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
OR a) Which process helps to transport water to the higher parts of the plants? b) Mention the function of the following digestive juices in the human alimentary canal. i) Gastric juice ii) Intestinal juice.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) Red colour ($RR$) flower producing pea plant is crossed with white colour ($rr$) flower producing pea plant. Show the result of $F_2$ generation with the help of checker board. b) How is the sex of male child be determined in humans?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) What is anaerobic respiration? What products will be produced in this process? b) What is double circulation of blood? How this type of blood circulation is advantageous to the birds and mammals?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Name the carbon compounds having the following structural formula: i) $H-C(H)(H)-C(H)(H)-C(H)(H)-Cl$ ii) $H-C(H)(H)-C(H)(H)-C(=O)H$ iii) $H-C(H)(H)-C\equiv C-H$ iv) $H-C(H)(H)-C(H)(H)-C(=O)OH$
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
