A man goes door to door posing as a goldsmith. He promises to bring back the glitter on dull gold ornaments. An unsuspecting woman gives a set of gold bangles to him which he dips in a particular solution. The bangles sparkle but their weight has considerably reduced. The solution used by the impostor probably is
conc. HCl
a mixture of conc. HCl and conc. HNO3
conc. HNO3
dil. HCl
While teaching the concept, 'force can change the shape of an object' to students, a teacher plans the following activities
A. Explain concepts using commonly observed examples.
B. Provide a dough on a plate and ask the students to press it down with the hand.
C. Show an audio-visual film explaining the concept with some examples.
The teacher is using different approaches to learning because
she knows she must follow her lesson plan
she wants to prepare students for a test
there are different kinds of learners in the class and she wants to address multiple intelligences
she wants to prove her knowledge
Which of the following can be assessed when Geeta is using only MCQ as a tool to assess "Nutrition in Humans"?
Misconceptions related to food habits
Learner's ability to apply knowledge and prepare a role-play to present in the morning assembly
Learners' ability to comprehend the importance of components of food and write a long essay
Analytical ability to classify food items and make a poster
When an iron nail is dipped in copper sulphate solution, the colour of copper sulphate solution fades and a brownish layer is deposited over the iron nail. This is an example of
decomposition reaction
double displacement reaction
displacement and redox reactions
combination reaction
A teacher plans to teach 'Components of Food' in Class-VI. Which of the following can be used as an essential question?
Why does your mother serve you a meal with a variety of food items?
Does your mother prepare a definite set of food items for lunch every day?
Do you eat all the items served in your lunch every day?
List the food items your mother serves you in lunch
Ms Patel, Principal of a School XYZ, is keen about integrated approach to teaching of Science rather than teaching different disciplines separately. The basis of this is
difficulty to adjust the teachers in the time-table
difficulty of students to adjust to different teachers
all the disciplines are interlinked and a teacher can draw on cross-curricular linkages
non-availability of qualified teachers in her school to teach separate disciplines
Bleeding is stopped by the application of alum to a wound because
alum coagulates the blood and forms a clot
alum reduces the temperature near the wound
alum is an antiseptic
the wound is plugged by the alum chunk
In which of the following cases of motion, are the distance moved and the magnitude of displacement equal?
A car moving in a circular path
A pendulum oscillating to and fro
The Earth revolving around the Sun
A car moving on a straight road
Adding salt and sugar to food substances helps in preserving them for a longer duration. It is because excess salt and sugar
cause rupturing of microbial cells
cause change in the shape of microbial cells
remove water from food
plasmolyse the microbial cells
