Class 10 Science Important MCQs: Get all important MCQs from CBSE Class 10th Science from all chapters to revise the key topics and concepts. These questions will help you in scoring excellent marks in CBSE Class 10 Science board exam 2023 on March 4, 2023.
These questions are accompanied by the right answers as well. However, you would get the answers to the important MCQs only towards the end. We have attached the answers in the PDF towards the end. This will help you attempt the questions without any distractions and you will be able to analyse your preparation as well.
CBSE Class 10 Science Important MCQs
Q1. In which of the following groups of organisms, food materials are broken down outside the body and absorbed?
(a) Mushroom, green plants, Amoeba
(b) Yeast, mushroom, bread mould
(c) Paramecium, Amoeba, Cuscuta
(d) Cuscuta, lice, tapeworm
Q2. The direction of force on a current carrying conductor in a magnetic field is given by
(a) Fleming’s left-hand rule.
(b) Fleming’s right-hand rule.
(c) Right hand thumb rule.
(d) Left hand thumb rule.
Q3. You are given water, mustard oil, glycerine and kerosene. In which of these media, a ray of light incident obliquely at same angle would bend the most?
(a) Kerosene
(b) Water
(c) Mustard oil
(d) Glycerine
Q4. In a synapse, chemical signal is transmitted from
(a) dendritic end of one neuron to axonal end of another neuron
(b) axon to cell body of the same neuron
(c) cell body to axonal end of the same neuron
(d) axonal end of one neuron to dendritic end of another neuron
Q5. Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is:
(a) 1: 1
(b) 2:1
(c) 4:1
(d) 1:2
Q6. A full length image of a distant tall building can definitely be seen by using:
(a) a concave mirror
(b) a convex mirror
(c) a plane mirror
(d) both concave as well as plane mirror
Q7. When Ag is exposed to air it gets a black coating of
(a) AgNO3
(b) Ag2S
(c) Ag2O
(d) Ag2CO3
Q8. The scattering of light by colloidal particles is called
(a) Tyndall effect
(b) dispersion
(c) atmospheric refraction
(d) internal reflection
Q9. Which of the reactions is used in black and white photography?
(a) Combination Reaction
(b) Decomposition Reaction
(c) Displacement reaction
(d) Oxidation reaction
Q10. IUCD is for
- Vegetative propagation
- Contraception
- Increasing fertility
- Avoiding miscarriage
Q11. Red colour is used as danger sign as
(A) red colour scattered least by smoke
(B) red colour scattered most by smoke
(C) Red colour absorbs by the smoke
(D) red colour moves fast in air
Q12.Sodium carbonate is a basic salt because it is a salt of a
(a) strong acid and strong base
(b) weak acid and weak base
(c) strong acid and weak base
(d) weak acid and strong base
Q13. The unit of resistivity is:
(a) V A
(b) V A
(c) V m /A
(d) VA/m
Q14. A doctor advised a person to take an injection of insulin because——-.
A) His blood pressure was low
B) His heart was beating slowly
C) He was suffering from goitre
D) His sugar level in blood was high
Q15. Which one of the given is true, if a substance has a pH value of 7?
(a) The substance is a base
(b) The substance is an acid
(c) The substance is a neutral substance
(d) Either (A) or (B)
Q16. The heating element of an electric iron is made up of:
(a) copper
(b) nichrome
(c) aluminium
(d) iron
Q17.The colour of phenolphthalein in acidic medium is-
(a) Yellow
(b) Pink
(c) Colourless
(d)Blue
Q18. Reason for the greater similarities among the off springs produced by asexual reproduction, is:
(i) Asexual reproduction involves only one parent
(ii) Asexual reproduction involves two parents
(iii) Asexual reproduction involves gametes
(iv) Asexual reproduction does not involve gametes
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iv)
(d) (i) and (iv)
Q19. Generally, when certain metals react with an acid they release gas.
(a) Nitrogen
(b) Oxygen
(c) Hydrogen
d) Argon
Q20.The genetic constitution of an individual organism is known as its
(a) phenotype
(b) homozygous
(c) genotype
(d) allele
Q21.Milkiness of lime water disappear when excess CO2 is passed due to the formation of-
(a) Calcium hydroxide
(b)Calcium chloride
(c) Calcium bicarbonate
(d)Calcium carbonate
Q22. The most abundant metal in the earth’s crust is
(a) Iron
(b) Aluminium
(c) Calcium
(d) Sodium
Q23.Which part of the DNA provides information for a protein?
(a) Chromosome
(b) Mitochondria
(c) RNA
(d) Gene
Q24. The electronic configuration of three elements X, Y and Z are as follows: X = 2, 4 Y = 2, 7 Z = 2,1 Which two elements will combine to form an ionic compound and write the correct formula,
(a) X2Y
(b) ZY
(c) XZ3
(d) Y2Z
Q25. Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?
(i) Good thermal conductivity
(ii) Good electrical conductivity
(iii) Ductility
(iv) High melting point
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (i) and (iv)
Q26. The brown gas evolved on heating of copper nitrate is
(a) O2
(b) NO2
(c) N2
(d) NO
Q27. A student makes an electric circuit using an LED, a battery and connecting wires to test the conductivity of distilled water. The student notices that the LED does not glow. He replaces the distilled water with a salt solution and observes that the LED glows. How does the salt solution help the LED to glow?
(a) Salt solution is covalent in nature and conducts electricity.
(b) Salt solution has a low melting point which allows the current to flow through it.
(c) Salt solution has a high boiling point which allows the flow of current in the circuit without getting hot.
(d) Salt solution contains ions which makes it conductive and allows the electricity to flow through it.
Q28. While cooking, if bottom of the vessel is getting blackened on the outside, it means that
(a)The food is not cooked properly
(b)The fuel is not burning properly
(c) The fuel is wet
(d)The fuel is burning completely
Q29. The chemical reaction shows the addition of chlorine gas to hydrocarbon in the presence of sunlight.
CHCl3 + Cl2 → CCl4 + HCl
How does chlorine react to a hydrocarbon compound in the presence of sunlight?
(a) it adds hydrogen into the compound
(b) it adds an oxygen atom into the compound
(c) it substitutes hydrogen atom from the compound
(d) it breaks double and triple bonds into a single bond
Q30. A carbon compound contains two atoms of carbon. Which name should the carbon compound bear?
(a) Butane
(b) Ethane
(c) Methane
(d) Propane
Q31. Environment includes:
(a) Land, air, water
(b) Light, temperature, rainfall
(c) Plants, animals, microbes
(d) All of these
Q32. The electronic configuration of an element is found to be 2, 4. How many bonds can one carbon atom form in a compound?
(a) 1
(b) 2
(c) 4
(d) 6
Q33. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm.
(b) mitochondria.
(c) chloroplast.
(d) nucleus.
Q34. Which group of waste materials can be classified as Non biodegradable ?
(a) Plant waste, used tea bags
(b) Polyethene bags, plastic toys
(c) Used tea bags, paper straw
(d) Old clothes, broken footwear
Q35. Coagulation of blood in a cut or wound is brought about by:
(a) plasma
(b) platelets
(c) WBC
(d) RBC
Q36. Which is the correct sequence of the components of a reflex arc?
(a) Receptors → Muscles → Sensory neuron → Motor neuron → Spinal cord
(b) Receptors → Motor neuron → Spinal cord → Sensory neuron → Muscle
(c) Receptors → Spinal cord → Sensory neuron → Motor neuron → Muscle
(d) Receptors → Sensory neuron → Spinal cord → Motor neuron → Muscle
Q37. Which of the following is a biodegradable waste ?
(a) DDT
(b) Aluminium can
(c) Plastic bag
(d) Cow dung
Q38. The two oviducts in a human female unite into an elastic bag like is known as
- Vagina
- Uterus
- Fallopian tube
- Cervix
Q39. The essential difference between an AC generator and a DC generator is that
(a) AC generator has an electromagnet while a DC generator has permanent magnet.
(b) DC generator will generate a higher voltage.
(c) AC generator will generate a higher voltage.
(d) AC generator has slip rings while the DC generator has a commutator.
Q40. Posture and balance of the body is controlled by
(a) cerebrum
(b) cerebellum
(c) medulla
(d) pons
Important resources for CBSE Class 10 Science Board Exam 2023 preparation
Important resources for CBSE Class 10 Board Exam 2023 preparation
- CBSE Class 10 Preparation Tips 2023: How to Prepare for Class 10th Board Exam?
- CBSE Class 10 Practice Papers: All Subjects
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